Tree of Perdition

Defender
{T}: Exchange target opponent's life total with this creature's toughness.

Hateflayer

Wither (This deals damage to creatures in the form of -1/-1 counters.)
{2}{R}, {Q}: This creature deals damage equal to its power to any target. ({Q} is the untap symbol.)

Buried Alive

Search your library for up to three creature cards, put them into your graveyard, then shuffle.

Mairsil, the Pretender

When Mairsil enters, you may exile an artifact or creature card from your hand or graveyard and put a cage counter on it.
Mairsil has all activated abilities of all cards you own in exile with cage counters on them. You may activate each of those abilities only once each turn.

Entomb

Search your library for a card, put that card into your graveyard, then shuffle.

Turn to Frog

Until end of turn, target creature loses all abilities and becomes a blue Frog with base power and toughness 1/1.