Martyr's Cause

Sacrifice a creature: The next time a source of your choice would deal damage to any target this turn, prevent that damage.

Adeline, Resplendent Cathar

Vigilance
Adeline, Resplendent Cathar's power is equal to the number of creatures you control.
Whenever you attack, for each opponent, create a 1/1 white Human creature token that's tapped and attacking that player or a planeswalker they control.

Martyr's Bond

Whenever Martyr's Bond or another nonland permanent you control is put into a graveyard from the battlefield, each opponent sacrifices a permanent that shares a card type with it.

Pyre of Heroes

{2}, {T}, Sacrifice a creature: Search your library for a creature card that shares a creature type with the sacrificed creature and has mana value equal to 1 plus that creature's mana value. Put that card onto the battlefield, then shuffle. Activate only as a sorcery.