Legendary Enchantment - Aura
Enchant creature you control
Enchanted creature has "G, t: Put a +1/+1 counter on target creature" and it assigns combat damage equal to X rather than its power, where X is the total number of counters on permanents you control.
Enchantment - Aura
Enchant Hydra creature
Whenever enchanted creature takes damage, its controller creates a token copy of it.
When ~ is put into a graveyard from the battlefield, exile all tokens created by it.
Kind of a big tweak, but I think it's still a fitting modification of the previous card;
Ora, the Rippling Mirror2RWUB
Legendary Creature - Sphinx Wizard
Whenever you cast an instant or sorcery spell, copy that spell. That copy gains lifelink and you may choose new targets for it.
Didn't start out legendary, or four color, but eventually wound up that way. *shrugs*
Creature - Zombie Wizard
Instant and sorcery card in your graveyard have "Flashback - X, Sacrifice a creature with converted mana cost X or greater, where X is the converted mana cost of this card."
Artifact Creature - Wizard Construct
When you cast ~ you may exile an instant or sorcery from you hand.
When ~ dies, you may cast the exiled card without paying its mana cost.
~ enters the battlefield tapped.
When you cast ~ you may search your library for an instant or sorcery card with converted mana cost 4 or less and exile it. 2, T, sacrifice~: Until end of turn, you may cast a card exiled with ~ without paying its mana cost.
Creature - Human Advisor
When you cast Crassius Curio, you may search your library for a Viashino and put it onto the battlefield. Shuffle your library if you do.
1/3 Plenty of time, my sweet.
Creature - Human Shaman
When ~ enters the battlefield, flip a coin. If you win the flip, exile ~, search your library for a Dragon creature card, put it onto the battlefield, then shuffle your library.
Search your library for a Dragon creature card. Then flip a coin, if heads. Put it into the battlefield. If tails, discard it and ~ deals damage equal to its power to target creature. Shuffle your library after.
Choose up to four non-land permanents and separate them into two piles. An opponent chooses one pile. For each permanent in that pile, create a token that's a copy of that permanent.