Hope you all are still kickin' it.
Here are some random ideas inspired by Chronicles of all things.
Stormfront Scourge 1UU
Creature - Drake
1/2
Flying U: Stormfront Scourge gets +1/+1 until end of turn. Return it to its owner's hand at end of turn. (Return it only if it's still in play.)
Diamond Dust 2W
Enchant Creature
As long as enchanted creature is white or an artifact, prevent all combat damage that would be dealt to it. Otherwise, prevent all combat damage that would be dealt by it.
Skyway
Land
Creatures with flying have haste. T: Add 1 to your mana pool.
Obstinate Sphinx 4W
Creature - Sphinx
4/4
Flying
When Obstinate Sphinx enters play, choose reach, first strike, trample, rampage, or landwalk.
Creatures with the chosen ability can't attack or block.
Spider Infestation 2G
Enchantment
At the end of your turn, sacrifice a permanent and put two 1/2 green Spider creature tokens with reach into play.
Spiders you control have banding.
Posthumous Combustion 1B
Sorcery
As an additional cost to cast Posthumous Combustion, exile a creature card from your graveyard.
Posthumous Combustion deals damage to target creature or player equal to the exiled card's power and damage to you equal to the exiled card's toughness.
Advanced Simulacrum 4
Artifact Creature
4/2
As long as Advanced Simulacrum is in play, it's not an artifact. (It's still a creature and still colorless.)
Perilous Trail 1G
Enchant Land
Scouts you control have landwalk of enchanted land's types.
When enchanted land leaves play, sacrifice a Scout.
Clockwork Curator 3
Artifact Creature
1/2
Vigilance
Clockwork Curator gets +1/+1 as long as you control a noncreature artifact.
Staging Grounds
Land T: Choose first strike, trample, vigilance, banding, or rampage 2. Target creature you control gains that ability until end of turn. Activate this ability only at a time you could cast a sorcery.
Mental Construct 4U
Creature - Illusion
3/5
When you control no Wizards, sacrifice Mental Construct.
Rampage 3 (Whenever this creature becomes blocked, it gets +3/+3 until end of turn for each creature blocking it beyond the first.)
Mark of Banishment W
Enchant Permanent
If enchanted permanent would leave play, exile it instead. It can't return to play from exile.
Boulder Barrage 3RR
Sorcery
Choose up to three target creatures and/or players, then discard that many land cards. If you do, Boulder Barrage deals 4 damage to each of those targets.
Strange Eruption 2U
Enchant Creature
Flash
Strange Eruption can only enchant a Wall.
Enchanted creature is a 5/3 black Wall Horror creature and can attack as though it didn't have defender.
Smoke Cover R
Sorcery
Target creature with flying can't block or be blocked this turn.
Skull Scrape 1BB
Sorcery
Skull Scrape deals damage to target player equal to 5 minus the number of cards in his or her hand.
Gnawing Worms 2BB
Creature - Insect
2/1
When Gnawing Worms is put into a graveyard from play, you may destroy target tapped permanent.
Reckless Pup 1R
Creature - Hound
2/2
Rampage 1 (Whenever this creature becomes blocked, it gets +1/+1 until end of turn for each creature blocking it beyond the first.)
At the beginning of your upkeep, sacrifice an artifact.
Shifting Caverns 1RR
Enchantment
Play with the top card of your library revealed.
As long as the top card of your library is a land card, creatures can't block.
Leper Colony 2WW
Creature - Human Leper
3/4
Whenever Leper Colony blocks or becomes blocked, put a -1/-1 counter on it and on each creature blocking it or blocked by it.
Deliberate XU
Sorcery
Look at the top X cards of your library. Put half of those cards, rounded up, into your hand and the rest into your graveyarad.
Leaden Arrow 1
Artifact 3,T, Sacrifice Leaden Arrow: Destroy target creature with flying. It can't be regenerated.
Fiery Ascension UR
Enchant Creature
Enchanted creature has flying.
When Fiery Ascension enters play, it deals 1 damage to each creature without flying.
Catharsis 1R
Instant
Exile your hand.
Add RRRRR to your mana pool.
Wraith Form 2BB
Enchantment
Prevent all combat damage that would be dealt to you.
Whenever a creature attacks you, you lose 1 life.
Gathering Stones 4W
Sorcery
Gain 8 life.
Return all cards with a converted mana cost of 1 from your graveyard to your hand.
Traveler's Prayer W
Instant
Prevent all damage that would be dealt to target creature this turn and next turn.
Choice Cut 3B
Instant
Choose one — Choice Cut deals 5 damage to target creature and you gain 2 life; or Choice Cut deals 2 damage to target creature and you gain 5 life.
Prune 1G
Sorcery
Look at the top seven cards of your library. Put two of those cards into your graveyard, then shuffle the remaining cards and put them back on top of your library.
Shade of Night's Wind 2B
Creature - Shade
0/1
Dash 0(You may cast this spell for its dash cost. If you do, it gains haste, and it’s returned from play to its owner’s hand at end of turn.) B: Shade of Night's Wind gets +1/+1 until end of turn.
Candy Count 3BB
Creature - Vampire
3/3
Flying
When Candy Count enters play, you lose 1 life for each candy you have and draw that many cards.
Costume (At any time, you may exile a creature card from your hand and pay its mana cost to have this creature become a copy of it.)
Stink Bomb 2BB
Sorcery
Trick or Treat (Any opponent may counter this spell by giving you a candy.)
Target opponent reveals his or her hand and discards all creature cards there.
Gobbling Goblin 3G
Creature - Goblin
4/5
At the beginning of your upkeep, sacrifice Gobbling Goblin unless you eat a candy.
Molten Chocolate 2R
Sorcery
Trick or Treat (Any opponent may counter this spell by giving you a candy.)
Molten Chocolate deals X damage to target creature or player, where X is the number of chocolate candies you have.
The idea here being that everyone gets a handful of candy and then plays in a tournament, and maybe gets more candy after each game or something.
Mietra's Intervention W
Instant
Regenerate target plains or white creature.
Volcanic Warmonger 4RR
Creature - Elemental Warrior
4/8
Other creatures you control attack if able.
Path of Purity WUG
Enchantment
When Path of Purity enters play, each player shuffles his or her graveyard into his or her library.
Creatures you control get +1/+1 for each graveyard with no cards in it.
Smog Belcher 5
Artifact Creature
3/3
Smog Belcher can’t be blocked by nonartifact creatures.
Prevent all damage that would be dealt to Smog Belcher by nonartifact creatures.
Blood Ritual 2R
Sorcery
Sacrifice any number of creatures. For each creature sacrificed this way, add BB to your mana pool and Blood Ritual deals 1 damage to each opponent.
Essence Hatch 1G
Instant
Destroy target artifact. Its controller puts a 3/3 colorless Spirit creature token into play.
Mirror Moon 1W
Enchantment
During your turn, all lands are basic Plains.
At the beginning of your upkeep, you may gain 1 life.
Skitter Scout 1
Artifact Creature - Scout
1/1
Whenever Skitter Scout becomes blocked, remove it from combat.
Invisible Reaver 1WUB
Creature - Spirit
5/3
Invisible Reaver can’t be blocked as long as the defending player has more life than you.
Crackling Aurora 1R
Enchantment
Lands you control have "T: Add one mana of any color to your mana pool. This land deals 1 damage to you."
Exhaustion Mage 2U
Creature - Human Wizard
1/2 T: Tap target attacking or blocking creature. It doesn’t untap during its controller’s next untap step.
Hideous Thing 1B
Creature - Beast
3/2
When you control any Humans, sacrifice Hideous Thing.
Wall of Glass 3
Artifact Creature - Wall
0/3
Defender
When Wall of Glass dies, put three 1/1 colorless Shard artifact creature tokens with defender into play.
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Here are some random ideas inspired by Chronicles of all things.
Stormfront Scourge 1UU
Creature - Drake
1/2
Flying
U: Stormfront Scourge gets +1/+1 until end of turn. Return it to its owner's hand at end of turn. (Return it only if it's still in play.)
Diamond Dust 2W
Enchant Creature
As long as enchanted creature is white or an artifact, prevent all combat damage that would be dealt to it. Otherwise, prevent all combat damage that would be dealt by it.
Skyway
Land
Creatures with flying have haste.
T: Add 1 to your mana pool.
Obstinate Sphinx 4W
Creature - Sphinx
4/4
Flying
When Obstinate Sphinx enters play, choose reach, first strike, trample, rampage, or landwalk.
Creatures with the chosen ability can't attack or block.
Spider Infestation 2G
Enchantment
At the end of your turn, sacrifice a permanent and put two 1/2 green Spider creature tokens with reach into play.
Spiders you control have banding.
Posthumous Combustion 1B
Sorcery
As an additional cost to cast Posthumous Combustion, exile a creature card from your graveyard.
Posthumous Combustion deals damage to target creature or player equal to the exiled card's power and damage to you equal to the exiled card's toughness.
Advanced Simulacrum 4
Artifact Creature
4/2
As long as Advanced Simulacrum is in play, it's not an artifact. (It's still a creature and still colorless.)
Perilous Trail 1G
Enchant Land
Scouts you control have landwalk of enchanted land's types.
When enchanted land leaves play, sacrifice a Scout.
Clockwork Curator 3
Artifact Creature
1/2
Vigilance
Clockwork Curator gets +1/+1 as long as you control a noncreature artifact.
Staging Grounds
Land
T: Choose first strike, trample, vigilance, banding, or rampage 2. Target creature you control gains that ability until end of turn. Activate this ability only at a time you could cast a sorcery.
Mental Construct 4U
Creature - Illusion
3/5
When you control no Wizards, sacrifice Mental Construct.
Rampage 3 (Whenever this creature becomes blocked, it gets +3/+3 until end of turn for each creature blocking it beyond the first.)
Mark of Banishment W
Enchant Permanent
If enchanted permanent would leave play, exile it instead. It can't return to play from exile.
Boulder Barrage 3RR
Sorcery
Choose up to three target creatures and/or players, then discard that many land cards. If you do, Boulder Barrage deals 4 damage to each of those targets.
Strange Eruption 2U
Enchant Creature
Flash
Strange Eruption can only enchant a Wall.
Enchanted creature is a 5/3 black Wall Horror creature and can attack as though it didn't have defender.
Smoke Cover R
Sorcery
Target creature with flying can't block or be blocked this turn.
Skull Scrape 1BB
Sorcery
Skull Scrape deals damage to target player equal to 5 minus the number of cards in his or her hand.
Gnawing Worms 2BB
Creature - Insect
2/1
When Gnawing Worms is put into a graveyard from play, you may destroy target tapped permanent.
Reckless Pup 1R
Creature - Hound
2/2
Rampage 1 (Whenever this creature becomes blocked, it gets +1/+1 until end of turn for each creature blocking it beyond the first.)
At the beginning of your upkeep, sacrifice an artifact.
Shifting Caverns 1RR
Enchantment
Play with the top card of your library revealed.
As long as the top card of your library is a land card, creatures can't block.
Leper Colony 2WW
Creature - Human Leper
3/4
Whenever Leper Colony blocks or becomes blocked, put a -1/-1 counter on it and on each creature blocking it or blocked by it.
Deliberate XU
Sorcery
Look at the top X cards of your library. Put half of those cards, rounded up, into your hand and the rest into your graveyarad.
Leaden Arrow 1
Artifact
3,T, Sacrifice Leaden Arrow: Destroy target creature with flying. It can't be regenerated.
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Enchant Creature
Enchanted creature has flying.
When Fiery Ascension enters play, it deals 1 damage to each creature without flying.
Catharsis 1R
Instant
Exile your hand.
Add RRRRR to your mana pool.
Wraith Form 2BB
Enchantment
Prevent all combat damage that would be dealt to you.
Whenever a creature attacks you, you lose 1 life.
Gathering Stones 4W
Sorcery
Gain 8 life.
Return all cards with a converted mana cost of 1 from your graveyard to your hand.
Wrecking Crew 3R
Creature - Dwarf Goblin Giant
3/3
RRR, T: Destroy target Wall, noncreature artifact, or nonbasic land.
Traveler's Prayer W
Instant
Prevent all damage that would be dealt to target creature this turn and next turn.
Choice Cut 3B
Instant
Choose one — Choice Cut deals 5 damage to target creature and you gain 2 life; or Choice Cut deals 2 damage to target creature and you gain 5 life.
Prune 1G
Sorcery
Look at the top seven cards of your library. Put two of those cards into your graveyard, then shuffle the remaining cards and put them back on top of your library.
Shade of Night's Wind 2B
Creature - Shade
0/1
Dash 0 (You may cast this spell for its dash cost. If you do, it gains haste, and it’s returned from play to its owner’s hand at end of turn.)
B: Shade of Night's Wind gets +1/+1 until end of turn.
1
Creature - Vampire
3/3
Flying
When Candy Count enters play, you lose 1 life for each candy you have and draw that many cards.
Costume (At any time, you may exile a creature card from your hand and pay its mana cost to have this creature become a copy of it.)
Stink Bomb 2BB
Sorcery
Trick or Treat (Any opponent may counter this spell by giving you a candy.)
Target opponent reveals his or her hand and discards all creature cards there.
Gobbling Goblin 3G
Creature - Goblin
4/5
At the beginning of your upkeep, sacrifice Gobbling Goblin unless you eat a candy.
Molten Chocolate 2R
Sorcery
Trick or Treat (Any opponent may counter this spell by giving you a candy.)
Molten Chocolate deals X damage to target creature or player, where X is the number of chocolate candies you have.
The idea here being that everyone gets a handful of candy and then plays in a tournament, and maybe gets more candy after each game or something.
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1
Instant
Regenerate target plains or white creature.
Volcanic Warmonger 4RR
Creature - Elemental Warrior
4/8
Other creatures you control attack if able.
Path of Purity WUG
Enchantment
When Path of Purity enters play, each player shuffles his or her graveyard into his or her library.
Creatures you control get +1/+1 for each graveyard with no cards in it.
Smog Belcher 5
Artifact Creature
3/3
Smog Belcher can’t be blocked by nonartifact creatures.
Prevent all damage that would be dealt to Smog Belcher by nonartifact creatures.
Blood Ritual 2R
Sorcery
Sacrifice any number of creatures. For each creature sacrificed this way, add BB to your mana pool and Blood Ritual deals 1 damage to each opponent.
Essence Hatch 1G
Instant
Destroy target artifact. Its controller puts a 3/3 colorless Spirit creature token into play.
Mirror Moon 1W
Enchantment
During your turn, all lands are basic Plains.
At the beginning of your upkeep, you may gain 1 life.
Skitter Scout 1
Artifact Creature - Scout
1/1
Whenever Skitter Scout becomes blocked, remove it from combat.
Invisible Reaver 1WUB
Creature - Spirit
5/3
Invisible Reaver can’t be blocked as long as the defending player has more life than you.
Crackling Aurora 1R
Enchantment
Lands you control have "T: Add one mana of any color to your mana pool. This land deals 1 damage to you."
Exhaustion Mage 2U
Creature - Human Wizard
1/2
T: Tap target attacking or blocking creature. It doesn’t untap during its controller’s next untap step.
Hideous Thing 1B
Creature - Beast
3/2
When you control any Humans, sacrifice Hideous Thing.
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It would be problematic for tournaments, but I still kinda like it.
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Artifact Creature - Wall
0/3
Defender
When Wall of Glass dies, put three 1/1 colorless Shard artifact creature tokens with defender into play.
Next: Upside-down wall!