I love Magic lore, but I'm not so familiar with the lore from OG dominaria. The things that I want are largely mechanics based. I really want commanders that make really niche lousy cards shine in a new context, much like The Gitrog Monster and Shirei, Shizo's Caretaker do. I'm honestly really tired of cookie-cutter 'EDH REC' style decks. Honestly, if I see your commander and your first few turns and can accurately predict 85% of your cards, its a real problem.
I had some ideas of stuff I would love as a commander. Honestly, there are tons of effects non-legendary creatures that I would love to have as commanders. Recent examples include Hostage Taker (a correctly worded version), Pathbreaker Ibex, Void Winnower, Crested Sunmare, or Gray Merchant of Asphodel. I think each of those could be flavored as legendary, and would lead to awesome, different deck styles.
Honestly, I think this isn't a good idea. We already have some commanders that 'break' color identity, and they are fine (Glissa, the Traitor, Wort, the Raidmother etc). We don't need a mechanic that so blatantly forces a change like this that only works in commander. Honestly, I think they should just print more legendary creatures with interesting abilities. More commanders that make obscure cards that aren't played in any other decks into allstars.
I'm honestly getting tired of looking at decks that look like EDHREC's most popular cards all slammed into one deck.
I think Training Grounds would be a high-profile tutor target in a deck like this. In that vein, other creatures that would benefit from the Training would go nicely here, maybe something like Dimir Guildmage or Azure Mage, or even something really cute like Pack Rat.
One of my favorite cards, Noxious Revival. Most of the time I use it sort of like a Vampiric Tutor. However, it can also be used to fizzle Reanimate, get rid of a juicy card in response to a fetch land/tutor, and is generally pretty efficient. Sure, its card disadvantage (most of the time) but its free and instant speed. Generally pretty happy to draw it in any green deck that can afford to play an instant.
Also late in the game you can use ito make an opponent draw a land/useless card for a turn if thats what you need to win. Its occasionally a time warp, for 0 mana.
Honestly, as someone who loves playing with creatures, Humility is the most annoying effect. Luckily it is essentially the only card with this effect. I know its not a keyword, but man does it suck to play against.
Granted, I love playing some of these cards, as they hose strategies that I don't like to play (Word of Law). I just understand how annoying they are to play against.
I have played Athreos! I love that deck, and (in my opinion) the superior cousin Shirei, Shizo's Caretaker.
Another thing I would love to see is a sweet Jund commander. It feels like whatever route you want to go, Prossh, Skyraider of Kher is the best at it, whether its tokens, voltron, combo, reanimator and so on. Having a red or black focused Jund commander that is better than Prossh at something.
Honestly, I just want sweet new commanders. The Gitrog Monster was one of the most mechanically interesting legendaries that I've seen in a long time, and would love to see more cards in the same vein. Basically any legendary that plays a different game than the rest of them. I want a card that screams for me to play a whole stack of different cards than any other deck. I'm kindof annoyed with the 'its a staple, so you should play it!' mentality (tutors, ramp, removal being largely similar/predictable in most decks).
I like playing decks with creatures and combat, so I would love a legend that allows me to do this.
A commander that allows for tons of spot removal would also be awesome.
Scenario 1:
I honestly don't mind. Sharing hidden information that you received (through in-game means) is fair game. You can choose not to share, of course, but if you think you could gain an advantage, I'd say go ahead. If you Thoughtseize a player and realize that they are about to win, telling the rest of the table is in your best interest.
I will preface this by noting that there will be many situations in which it is not in your best interest to reveal hidden information. If what a player is about to do is not particularly threatening, revealing information may get some ill will towards you later in the game.
If this was done against me, I wouldn't really be annoyed with it.
Scenario 2:
This is a perfect teaching moment, showcasing proper threat assessment. Also, it is worth noting that Magic is a difficult game, and Commander is even more so. Commander is more prone to biases and metagaming than just about any other format. However, this sort of attitude is exactly how the 'arms race' begins in playgroups. One player feels like they are unfairly targeted, so they increase the power to their deck to compensate, in order to counteract the potential 3v1 scenario. This leads to an even more justified 3v1 mentality, and so the cycle continues. Its easy to say 'get gud scrub' and call it a day.
If it becomes a persistent issue, I would recommend speaking up mid-game, and showcasing scenarios about proper threat assessment. After the game, maybe discuss deck-building and including more spot removal/boardwipes/gravehate/whatever. Maybe point them towards cheap ($$$) cards that will improve their deck. Small things like this really help.
I've used Teferi's Veil to great effect in my Tymna the Weaver/Thrasios, Triton Hero weenies deck. All my creatures are small and wouldn't block anyways, and this helps all my creatures avoid sorcery speed removal and wraths. Its a pretty sweet card. I guess I also play Submerge in that deck, as well as a few other cards listed here. Cursed Totem, Delay have performed well in a deck full of 1 mana 1/1s.
A hidden gem I would offer is Beckon Apparition. The foil is beautiful (and cheap!) and can really but the hurt on in competitive metas. Plus getting a flying token at instant speed isn't too shabby either. Especially when the token draws you a card every turn cuz of tymna, but its still good either way.
Fragmentize and Natural State are also underplayed, especially when looking at the superior Nature's Claim, but I think they are worth running in competitive metas, with artifact mana everywhere.
Suppression Field is one of my favorite cards, and it stops tons of combos. It slows down superfriends, Thrasios, hermit druid, and tons of commanders. It hurts fetchlands as well. If you play in a 'competitive' group but don't have a competitive deck, this card will go a long way.
Mystic Confluence is awesome. Its a strictly better Ingenuity, and a counterspell you don't mind cascading into. I would consider this card a staple. Its also a great piece of interaction in a deck that doesn't have a whole lot. I used all ten modes a few times each. Sometimes its a hardcasted Force of Will. Sometimes you draw 3 at the end of an opponents turn. Sometimes it gets rid of three blockers/hatebears. Sometimes you have tons of mana and no gas and you use it to bounce Wanderer back to your hand and draw 2. Sometimes you cascade into it and use it to counter wanderer on a board where you can't profitably attack, so you can cast him the next turn for only 8 mana. Mana leak + draw 2 is very strong on occasion. There basically isn't a situation where you have 5 mana and Mystic Confluence is not good.
Treachery, Bribery, are better than Stolen Identity, as its not the best cascade card on an empty board. At least with Treachery you can always cast it on your own creature for 5 more mana if you cascade into it. Its not a bad card, and I would play it if I didn't have better options in the 6 slot.
One of the better ways to test the 'competitiveness' is to goldfish the deck a whole lot of times (100 minimum), and to keep track on the turn that you would win. More 'competitive' decks can do this 75%~ by turn 5.
I had some ideas of stuff I would love as a commander. Honestly, there are tons of effects non-legendary creatures that I would love to have as commanders. Recent examples include Hostage Taker (a correctly worded version), Pathbreaker Ibex, Void Winnower, Crested Sunmare, or Gray Merchant of Asphodel. I think each of those could be flavored as legendary, and would lead to awesome, different deck styles.
Honestly, the thing I want more than anything is an interesting Boros commander that provides some sort of card advantage (Blaze Commando, Assemble the Legion or Tamanoa anyone?) and isn't super combat heavy. Maybe a Training Grounds type effect. Maybe a tutor for artifacts/enchantments like a Hoarding Dragon/Totem-Guide Hartbeest that really appreciates Blood Moon/Ensnaring Bridge. Spitemare/Boros Reckoner could be pretty sweet, and the Reckoner could easily be flavored as legendary.
I'm just rambling now.
I'm honestly getting tired of looking at decks that look like EDHREC's most popular cards all slammed into one deck.
With all the untapping, I would definitely recommend Chord of Calling.
Also late in the game you can use ito make an opponent draw a land/useless card for a turn if thats what you need to win. Its occasionally a time warp, for 0 mana.
I'm guilty of playing many of these next cards. Most of them are in the same deck. Basically enchantments/artifacts that prevent whole archetypes from working. Rest in Peace, Null Rod, Word of Law, Stranglehold, Notion Thief, Cursed Totem, Torpor Orb, Suppression Field, Blood Moon, Aura Shards, Grave Pact and a few others. These types of cards basically scream "Remove me or you won't be able to play at all!"
Granted, I love playing some of these cards, as they hose strategies that I don't like to play (Word of Law). I just understand how annoying they are to play against.
Another thing I would love to see is a sweet Jund commander. It feels like whatever route you want to go, Prossh, Skyraider of Kher is the best at it, whether its tokens, voltron, combo, reanimator and so on. Having a red or black focused Jund commander that is better than Prossh at something.
I like playing decks with creatures and combat, so I would love a legend that allows me to do this.
A commander that allows for tons of spot removal would also be awesome.
I honestly don't mind. Sharing hidden information that you received (through in-game means) is fair game. You can choose not to share, of course, but if you think you could gain an advantage, I'd say go ahead. If you Thoughtseize a player and realize that they are about to win, telling the rest of the table is in your best interest.
I will preface this by noting that there will be many situations in which it is not in your best interest to reveal hidden information. If what a player is about to do is not particularly threatening, revealing information may get some ill will towards you later in the game.
If this was done against me, I wouldn't really be annoyed with it.
Scenario 2:
This is a perfect teaching moment, showcasing proper threat assessment. Also, it is worth noting that Magic is a difficult game, and Commander is even more so. Commander is more prone to biases and metagaming than just about any other format. However, this sort of attitude is exactly how the 'arms race' begins in playgroups. One player feels like they are unfairly targeted, so they increase the power to their deck to compensate, in order to counteract the potential 3v1 scenario. This leads to an even more justified 3v1 mentality, and so the cycle continues. Its easy to say 'get gud scrub' and call it a day.
If it becomes a persistent issue, I would recommend speaking up mid-game, and showcasing scenarios about proper threat assessment. After the game, maybe discuss deck-building and including more spot removal/boardwipes/gravehate/whatever. Maybe point them towards cheap ($$$) cards that will improve their deck. Small things like this really help.
A hidden gem I would offer is Beckon Apparition. The foil is beautiful (and cheap!) and can really but the hurt on in competitive metas. Plus getting a flying token at instant speed isn't too shabby either. Especially when the token draws you a card every turn cuz of tymna, but its still good either way.
Fragmentize and Natural State are also underplayed, especially when looking at the superior Nature's Claim, but I think they are worth running in competitive metas, with artifact mana everywhere.
Suppression Field is one of my favorite cards, and it stops tons of combos. It slows down superfriends, Thrasios, hermit druid, and tons of commanders. It hurts fetchlands as well. If you play in a 'competitive' group but don't have a competitive deck, this card will go a long way.
Treachery, Bribery, are better than Stolen Identity, as its not the best cascade card on an empty board. At least with Treachery you can always cast it on your own creature for 5 more mana if you cascade into it. Its not a bad card, and I would play it if I didn't have better options in the 6 slot.
Etali, Primal Storm is sweet, but is not as impactful as other 6 drops like Pathbreaker Ibex or Scourge of the Throne. I wouldn't fault you for playing it, cuz its super sweet.