Xu-Ifit, Osteoharmonist

{T}: Return target creature card from your graveyard to the battlefield. It's a Skeleton in addition to its other types and has no abilities. Activate only as a sorcery.

Leveler

When this creature enters, exile all cards from your library.

Devouring Strossus

Flying, trample
At the beginning of your upkeep, sacrifice a creature.
Sacrifice a creature: Regenerate this creature.

Abyssal Persecutor

Flying, trample
You can't win the game and your opponents can't lose the game.

Kuro, Pitlord

At the beginning of your upkeep, sacrifice Kuro unless you pay {B}{B}{B}{B}.
Pay 1 life: Target creature gets -1/-1 until end of turn.

Shadow of Mortality

If your life total is less than your starting life total, this spell costs {X} less to cast, where X is the difference.

Colossus of Akros

Defender, indestructible
{10}: Monstrosity 10. (If this creature isn't monstrous, put ten +1/+1 counters on it and it becomes monstrous.)
As long as this creature is monstrous, it has trample and can attack as though it didn't have defender.

Yargle, Glutton of Urborg

Colossus of Sardia

Trample (This creature can deal excess combat damage to the player or planeswalker it's attacking.)
This creature doesn't untap during your untap step.
{9}: Untap this creature. Activate only during your upkeep.

Eater of Days

Flying, trample
When this creature enters, you skip your next two turns.

Metalwork Colossus

This spell costs {X} less to cast, where X is the total mana value of noncreature artifacts you control.
Sacrifice two artifacts: Return this card from your graveyard to your hand.