Dismember

({B/P} can be paid with either {B} or 2 life.)
Target creature gets -5/-5 until end of turn.

Kin-Tree Invocation

Create an X/X black and green Spirit Warrior creature token, where X is the greatest toughness among creatures you control.

Tower Defense

Creatures you control get +0/+5 and gain reach until end of turn.

Tree of Perdition

Defender
{T}: Exchange target opponent's life total with Tree of Perdition's toughness.

Assault Formation

Each creature you control assigns combat damage equal to its toughness rather than its power.
{G}: Target creature with defender can attack this turn as though it didn't have defender.
{2}{G}: Creatures you control get +0/+1 until end of turn.

Tree of Redemption

Defender
{T}: Exchange your life total with Tree of Redemption's toughness.

Doran, the Siege Tower

Each creature assigns combat damage equal to its toughness rather than its power.

Overgrown Battlement

Defender
{T}: Add {G} for each creature you control with defender.

Tragic Slip

Target creature gets -1/-1 until end of turn.
Morbid — That creature gets -13/-13 until end of turn instead if a creature died this turn.

Behind the Scenes

Creatures you control have skulk. (They can't be blocked by creatures with greater power.)
{4}{W}: Creatures you control get +1/+1 until end of turn.

Severed Strands

As an additional cost to cast this spell, sacrifice a creature.
You gain life equal to the sacrificed creature's toughness. Destroy target creature an opponent controls.