Major Wood-Rotted Root

This palm-sized chunk of wood it rotting, and riddled with mold and fungi. You can crush this wood to use it as a spell catalyst when you cast a oaken resilience. When you do, the bark that covers your skin is rotting, and emits a small cloud of spores whenever you're hurt. For the duration, whenever you take physical damage, your rotting bark skin emits a cloud of spores in the listed emanation. Creatures in the area must attempt a Fortitude save at the listed DC to avoid taking the listed poison damage.