Coralhelm Guide

At the beginning of your upkeep, put target creature card from a graveyard onto the battlefield under your control.

Whenever a creature you control attacks, it gets +1/+0 until end of turn for each other attacking creature that shares a creature type with it.

Add {B} for each creature card in your graveyard.

Whenever a creature you control dies, each other player sacrifices a creature.

Creatures you control get +3/+3 and gain trample until end of turn.