The Bestiary provides card advantage slowly, but can make an awful lot of it. Green decks tend to have a ton of creatures, so it's not too hard to find things to play for an extra card. Needing to pay an mana every time can be irritating, but the rate of 1 mana to make the creature is a cantrip is a good deal, and green decks often have enough mana that you can afford it. It makes your mana elfs a much better draw late game by effectively letting you cycle them.
Even when doing a Thassa, God of the Sea or Search for Azcanta impression by just scrying every turn, it's not an awful deal. The scry can help set you up to draw more card by removing non-creatures from the top of your deck.
The downside of the Bestiary is, like most card drawing spells, that's all it does. You can spend a lot of mana on it without impacting the board. However, the fact that it's rewarding you for impacting the board by playing creatures alleviates this somewhat.
The biggest Ajani follows the classic planeswalker pattern of "+ to draw, - to remove a creature, Ult to win", though with a couple of interesting wrinkles. Swords to Plowshares is a nice removal spell and Ajani's loyalty costs allow you to cast it every other turns. The card draw ranges between good and really terrible depending on the makeup of your deck. In a control deck that's playing a lot of instants and sorceries, it will be pretty bad, but fortunately, most controlling green and white decks will have a reasonable number of value creatures. 6 mana is a tough spot for planeswalkers, and dealing with a single creature on the turn it comes into play just doesn't cut when compared to a card like Elspeth, Sun's Champion or Chandra, Flamecaller.
Graveyard Marshal is in the unfortunate position of being a CC 2-drop. Many years ago, there were a number of double colored mana cards making the 2-drop section of even the smallest cubes (Soltari Priest, Ember Hauler, Nantuko Shade). These were challenging to play consistently in 2 color decks, especially if you had CC cards in two different colors. As Wizards continues to print good 2 drop creatures at both 1C and CC mana costs, those with less strict casting requirements have mostly out-competed more difficult to cast ones. Some CC creatures are powerful enough to be worth it and some cube managers even like that a CC forces drafters to more heavily commit to a color. The question is, does the Marshal make the cut? 3/2 is a good size body for only 2 mana, and the ability to turn previously killed creature into tokens can provide a form of reach for aggressive decks. If it only cost one colored mana, I think Marshal would compete with some of blacks best two drops. With its actual mana cost, it seems like a good option for larger cubes or those pushing strategies requiring higher color commitment.
Arcane Artisan is a somewhat surprising new enabler for cheating creatures into play, which in the last few years has received many great targets to put into play, but not many new ways to do it. As a small-bodied creature that needs to tap to do anything, Artisan draws comparisons to Elvish Piper. Compared to Piper, Artisan has several downsides: it costs more mana to activate, making it less likely you get to play another spell on the same turn, and is more weak to removal once it's been in play, since if it dies, so does your cheated creature. However, Artisan has the big advantage that of costing one fewer mana, which is extremely valuable and places it a level above the Piper. Acting as an expensive Merfolk Looter or giving you a free card every time you cheat something into play is also nice. Another side benefit for cube construction is that it deepens Blue's support for cheating decks, which historically has been limited to powerhouse Tinker and Show and Tell.
The next few cards will be coming from the most recent update to MTGO's legacy cube, since that seems to be a good source of cards that haven't been talked about in this thread.
A 5 mana 3/3 needs to do a lot to justify its cost. Her upper limit is very high (Fastbond and keep drawing until you run out of lands), but her average case of draw 1 to 2 cards a turn isn't too impressive. Playing lands is definitely something green is good at and green really appreciates extra card draw (see the popularity of Harmonize compared to Concentrate). However, to play Tatyova, you also need to be blue, which has many higher-powered card draw spells.
For a color that's so devoted to attacking, red's 3 drops aren't that great of solo attackers. There are now 4 good token producers, most of which want to be attacking, but they're not so impressive without the tokens they make. Red 3's also have utility or combo creature like Imperial Recruiter and Feldon of the Third Path , but they don't fit very well in aggro. Ferocidon has a good body for a 3 drop and evasion in the form of menace, as well as punishing your opponent for playing blockers. Incidental life gain hate never hurts either.
Champion combines a reasonable body along with a card selection. If you can afford to wait until late game, eternalize will pay off big with card draw + a bigger body. As always, looting is especially valuable in reanimator decks, but all blue decks can get respectable value off of a blocker to hold off opposing aggro decks while they sculpt their hand.
One of the biggest equipment / vehicle there is, Skysovereign asks a lot of you in terms of mana and creatures to crew it, but gives a lot in return. Its titan-esque ability to kill something when it comes into play and then again every time you attack with it, in addition to its 6 power in the air, lets it quickly take over any board it's played on. Unlike a titan, it's not great to cheat into play, because you still need to be able to crew it.
BONUS QUESTION
There's a limit to how many vehicles / equipment / creature auras you can play in most decks, because they require creatures to do anything. Is there a limit to how many of these effects you would play in your cube, assuming an infinite number of "good enough" ones. If so, how close to that limit are you?
Dark-Dwellers do an interesting impression of Snapcaster Mage. In the best possible case where you get/want to play a 3 CMC spell from your graveyard at sorcery speed, then they're upgrading the body from a 2/1 to a 4/4 menace for the same total mana cost. However, you lose a lot of flexibility for this best case scenario. You will never be able to recast countermagic or cast this on your opponent's end step, and the mana efficiency gets worse the cheaper of a card you recast, not to mention that you're waiting until turn 5 no matter what.
Dark-Dwellers is an interesting curve-topper in aggro, letting you rebuy a burn spell either for face damage or to clear out a blocker and then leaving a relevant body if that didn't close up the game. It also fits well into more midrange or controlling red decks by giving a mana efficient 2-for-1.
BONUS QUESTION
Some cubes support mostly / only aggressive red decks with smaller creature and burn spells, but many also support midrange or controlling red/X decks. What cards do you think are most important to support Big Red?
Man-o'-War is the original bounce spell attached to a creature and certainly one of the best. There have been several near reprints in Aether Adept and Exclusion Mage, as well as more expensive versions. One variant that has stood out recently has been Reflector Mage. Man-o'-War can provide a ton of tempo against expensive creatures, and against smaller creatures can trade while still giving some valuable tempo. It also has some more combo-rific uses bouncing your own creatures to reuse enters the battlefield effects.
BONUS QUESTION
Attaching a bounce spell to a creature moves Unsummon from being mostly unplayable in cube to being much more powerful. What other spell effects would you like to see attached to a creature in order to make them more playable in cube?
It was literally in both of the decks that just made the finals of the World Championship, and sees regular play in Standard's most popular archetype.
It's also used in Modern, played well in Legacy and even has made some Vintage appearances too.
Oh, whoops. I probably shouldn't post about formats I know nothing about when trying to come up with an intro for the card. My standard play is limited to MTG Arena, where I think I've only seen a Karn cast once. I took a quick look at mtggoldfish and missed copies in the sideboard (and sometimes the mainboard) of RB.
This Karn has struggled to find its place in constructed formats, but in cube it's a different story. It offers affordable card advantage and bodies to protect itself to midrange decks of any colors. His -2 is even better in the artifact deck, where it can make a giant body, rather than the usual 1/1 or 2/2.
BONUS QUESTION
Colorless cards can be played in any color of deck, but often work better in some colors than others. What colorless cards in your cube are most often played in certain colors?
I don't know if this is what DadOfGideon is referring to, but there's a wrong interpretation of the printed text of Book Burning that reads it like "(Unless a player has Book Burning) deal 6 damage to him or her [and] put the top six cards of target player's library into his or her graveyard."
So unless you "have" a copy of Book Burning, you take 6 damage and mill 6. This requires several weird interpretations of English grammar, including reading the comma as though it meant "and".
Painful Truths pushes you to play more colors in order to maximize it's effect. I don't currently play it at 360, but it's towards the top of my list if looking for a black draw spell.
Card draw can be a bit boring, even when it's powerful. What's the most interesting draw effect you play?
Yeah, I'd kind of like to keep in Jungle Lion, but that card, along with all of the other aggressive green 1-drops, were super unpopular with my group. So I just took them out. There was just no point in having them in my cube if they got taken 15th every time unless I picked them. So I've been trying out a couple of green 2 drops, including Mayor of Avabruck and Jungle Lion. Both of those have not been very impressive. I think maybe I'll try out Rofellos, Llanowar Emissary. Does anyone have experience with that card?
Lifecrafter's Bestiary (Replacing Oath of Nissa)
The Bestiary provides card advantage slowly, but can make an awful lot of it. Green decks tend to have a ton of creatures, so it's not too hard to find things to play for an extra card. Needing to pay an mana every time can be irritating, but the rate of 1 mana to make the creature is a cantrip is a good deal, and green decks often have enough mana that you can afford it. It makes your mana elfs a much better draw late game by effectively letting you cycle them.
Even when doing a Thassa, God of the Sea or Search for Azcanta impression by just scrying every turn, it's not an awful deal. The scry can help set you up to draw more card by removing non-creatures from the top of your deck.
The downside of the Bestiary is, like most card drawing spells, that's all it does. You can spend a lot of mana on it without impacting the board. However, the fact that it's rewarding you for impacting the board by playing creatures alleviates this somewhat.
The biggest Ajani follows the classic planeswalker pattern of "+ to draw, - to remove a creature, Ult to win", though with a couple of interesting wrinkles. Swords to Plowshares is a nice removal spell and Ajani's loyalty costs allow you to cast it every other turns. The card draw ranges between good and really terrible depending on the makeup of your deck. In a control deck that's playing a lot of instants and sorceries, it will be pretty bad, but fortunately, most controlling green and white decks will have a reasonable number of value creatures. 6 mana is a tough spot for planeswalkers, and dealing with a single creature on the turn it comes into play just doesn't cut when compared to a card like Elspeth, Sun's Champion or Chandra, Flamecaller.
Graveyard Marshal is in the unfortunate position of being a CC 2-drop. Many years ago, there were a number of double colored mana cards making the 2-drop section of even the smallest cubes (Soltari Priest, Ember Hauler, Nantuko Shade). These were challenging to play consistently in 2 color decks, especially if you had CC cards in two different colors. As Wizards continues to print good 2 drop creatures at both 1C and CC mana costs, those with less strict casting requirements have mostly out-competed more difficult to cast ones. Some CC creatures are powerful enough to be worth it and some cube managers even like that a CC forces drafters to more heavily commit to a color. The question is, does the Marshal make the cut? 3/2 is a good size body for only 2 mana, and the ability to turn previously killed creature into tokens can provide a form of reach for aggressive decks. If it only cost one colored mana, I think Marshal would compete with some of blacks best two drops. With its actual mana cost, it seems like a good option for larger cubes or those pushing strategies requiring higher color commitment.
Arcane Artisan is a somewhat surprising new enabler for cheating creatures into play, which in the last few years has received many great targets to put into play, but not many new ways to do it. As a small-bodied creature that needs to tap to do anything, Artisan draws comparisons to Elvish Piper. Compared to Piper, Artisan has several downsides: it costs more mana to activate, making it less likely you get to play another spell on the same turn, and is more weak to removal once it's been in play, since if it dies, so does your cheated creature. However, Artisan has the big advantage that of costing one fewer mana, which is extremely valuable and places it a level above the Piper. Acting as an expensive Merfolk Looter or giving you a free card every time you cheat something into play is also nice. Another side benefit for cube construction is that it deepens Blue's support for cheating decks, which historically has been limited to powerhouse Tinker and Show and Tell.
Tatyova, Benthic Druid (Replacing Kiora's Follower)
A 5 mana 3/3 needs to do a lot to justify its cost. Her upper limit is very high (Fastbond and keep drawing until you run out of lands), but her average case of draw 1 to 2 cards a turn isn't too impressive. Playing lands is definitely something green is good at and green really appreciates extra card draw (see the popularity of Harmonize compared to Concentrate). However, to play Tatyova, you also need to be blue, which has many higher-powered card draw spells.
For a color that's so devoted to attacking, red's 3 drops aren't that great of solo attackers. There are now 4 good token producers, most of which want to be attacking, but they're not so impressive without the tokens they make. Red 3's also have utility or combo creature like Imperial Recruiter and Feldon of the Third Path , but they don't fit very well in aggro. Ferocidon has a good body for a 3 drop and evasion in the form of menace, as well as punishing your opponent for playing blockers. Incidental life gain hate never hurts either.
Champion combines a reasonable body along with a card selection. If you can afford to wait until late game, eternalize will pay off big with card draw + a bigger body. As always, looting is especially valuable in reanimator decks, but all blue decks can get respectable value off of a blocker to hold off opposing aggro decks while they sculpt their hand.
Skysovereign, Consul Flagship
One of the biggest equipment / vehicle there is, Skysovereign asks a lot of you in terms of mana and creatures to crew it, but gives a lot in return. Its titan-esque ability to kill something when it comes into play and then again every time you attack with it, in addition to its 6 power in the air, lets it quickly take over any board it's played on. Unlike a titan, it's not great to cheat into play, because you still need to be able to crew it.
BONUS QUESTION
There's a limit to how many vehicles / equipment / creature auras you can play in most decks, because they require creatures to do anything. Is there a limit to how many of these effects you would play in your cube, assuming an infinite number of "good enough" ones. If so, how close to that limit are you?
Dark-Dwellers do an interesting impression of Snapcaster Mage. In the best possible case where you get/want to play a 3 CMC spell from your graveyard at sorcery speed, then they're upgrading the body from a 2/1 to a 4/4 menace for the same total mana cost. However, you lose a lot of flexibility for this best case scenario. You will never be able to recast countermagic or cast this on your opponent's end step, and the mana efficiency gets worse the cheaper of a card you recast, not to mention that you're waiting until turn 5 no matter what.
Dark-Dwellers is an interesting curve-topper in aggro, letting you rebuy a burn spell either for face damage or to clear out a blocker and then leaving a relevant body if that didn't close up the game. It also fits well into more midrange or controlling red decks by giving a mana efficient 2-for-1.
BONUS QUESTION
Some cubes support mostly / only aggressive red decks with smaller creature and burn spells, but many also support midrange or controlling red/X decks. What cards do you think are most important to support Big Red?
Man-o'-War is the original bounce spell attached to a creature and certainly one of the best. There have been several near reprints in Aether Adept and Exclusion Mage, as well as more expensive versions. One variant that has stood out recently has been Reflector Mage. Man-o'-War can provide a ton of tempo against expensive creatures, and against smaller creatures can trade while still giving some valuable tempo. It also has some more combo-rific uses bouncing your own creatures to reuse enters the battlefield effects.
BONUS QUESTION
Attaching a bounce spell to a creature moves Unsummon from being mostly unplayable in cube to being much more powerful. What other spell effects would you like to see attached to a creature in order to make them more playable in cube?
Oh, whoops. I probably shouldn't post about formats I know nothing about when trying to come up with an intro for the card. My standard play is limited to MTG Arena, where I think I've only seen a Karn cast once. I took a quick look at mtggoldfish and missed copies in the sideboard (and sometimes the mainboard) of RB.
Karn, Scion of Urza
This Karn has struggled to find its place in constructed formats, but in cube it's a different story. It offers affordable card advantage and bodies to protect itself to midrange decks of any colors. His -2 is even better in the artifact deck, where it can make a giant body, rather than the usual 1/1 or 2/2.
BONUS QUESTION
Colorless cards can be played in any color of deck, but often work better in some colors than others. What colorless cards in your cube are most often played in certain colors?
So unless you "have" a copy of Book Burning, you take 6 damage and mill 6. This requires several weird interpretations of English grammar, including reading the comma as though it meant "and".
Painful Truths
Painful Truths pushes you to play more colors in order to maximize it's effect. I don't currently play it at 360, but it's towards the top of my list if looking for a black draw spell.
Card draw can be a bit boring, even when it's powerful. What's the most interesting draw effect you play?