Obtained from Spooky! Youkai Cemetery Special Event dungeon.
Works like a Resolve-type effect; leaves you with 1 HP upon suffering fatal damage one time.
As noted, it grants an excellent 35% Skill Boost to any Attack Skill.
However, it's a bit of a double-edged sword as it also self-inflicts Zombify on you.
Pretty good sub if you can work around the Zombify effect. Otherwise, be wary of using it.
The Gashadokuro are giant skeletons that are fifteen times taller than an average person, said to be created from the amassed bones of people who died of starvation.
These Yōkai roam after midnight, grabbing lone travelers and biting off their heads to drink in their spraying blood.