So these are my first magic dream cards, but I like the idea behind them.
Soul Bind - Enchantment -
Enchant target creature you control. You gain X life, where X is that creature's power and toughness combined. Then that creature gains +X/+X and lifelink, where X is your life total. When enchanted creature is put to the graveyard, you lose the game.
: Enchanted creature gains protection from chosen color until the end of turn.
Form Entwine - Enchantment -
Target player chooses to enchant target creature they control. That creature gains +X/+X and
trample, where X is that player's life total. When enchanted creature is put to the graveyard, the creature's owner loses the game.
: Regenerate enchanted creature.
Necrotic Chimera - Enchantment -
Enchant target creature in any graveyard. Put that creature into play under your control. That creature gains +X/+X, where X is your life total. You lose the game if the creature card is in your graveyard at the end of the turn.
If the enchanted creature would be put to the graveyard at any time, you may pay
. If you do, return that creature card and this enchantment enchanting it to play.
Illusionary Attachment - Enchantment -
You chooses to enchant target creature any player controls. That creature gains +X/+X and shroud, where X is that creature's controller's life total. When enchanted creature is put to the graveyard, the creature's owner loses the game.
: Enchanted creature gains flying until the end of turn.
Rage Unison - Enchantment -
Enchant target creature you control. That creature gains +X/+X and first strike, where X is your life total. When enchanted creature is put to the graveyard, the creature's owner loses the game.
, Pay X life. Enchanted creature deals X damage to target player or creature.
The idea behind them is that the planeswalker controlling the creature is binding with them in some form to augment their power, at the cost of leaving themselves open to attack from any card that kills creatures. All of them have (expensive) plans to deal with these problems, except unthinking red. However, red gets arguably the most powerful card. Some of them are also fun because they can make another player enchant one of their own creatures. For flavor reasons, they would have to say something prohibiting each player from controlling more than one enchanted creature. They all make for pretty powerful cards. Imagine soul bind with Felidar Sovreign!