Pathbreaker Ibex

Whenever this creature attacks, creatures you control gain trample and get +X/+X until end of turn, where X is the greatest power among creatures you control.

Forbidden Orchard

{T}: Add one mana of any color.
Whenever you tap this land for mana, target opponent creates a 1/1 colorless Spirit creature token.

Bloodspore Thrinax

Devour 1 (As this creature enters, you may sacrifice any number of creatures. It enters with that many +1/+1 counters on it.)
Each other creature you control enters with an additional X +1/+1 counters on it, where X is the number of +1/+1 counters on this creature.

Eldrazi Monument

Creatures you control get +1/+1 and have flying and indestructible.
At the beginning of your upkeep, sacrifice a creature. If you can't, sacrifice this artifact.

Sekki, Seasons' Guide

Sekki enters with eight +1/+1 counters on it.
If damage would be dealt to Sekki, prevent that damage, remove that many +1/+1 counters from Sekki, and create that many 1/1 colorless Spirit creature tokens.
Sacrifice eight Spirits: Return this card from your graveyard to the battlefield.

Asceticism

Creatures you control have hexproof.
{1}{G}: Regenerate target creature. (The next time it would be destroyed this turn, instead tap it, remove it from combat, and heal all damage on it.)

Lifeline

Whenever a creature dies, if another creature is on the battlefield, return the first card to the battlefield under its owner's control at the beginning of the next end step.