Like the other two Mausoleums before this one, Mausoleum III is fairly easy but adds a new ghost type. You’ll find Mausoleum III in Inkwell Isle III, just after defeating Captain Brineybeard in “Shootin N’ Lootin.” As always, walk up to it and enter to start your urn protection trial.
Guard the Urn
When Mausoleum III starts, you will have to guard the urn just as you have twice before. All of the same ghosts will return. So basically, you will have normal floaty ghosts, old men ghosts and girl ghosts. The only real addition are these creepy looking Mr. Hyde ghosts.
This is essentially just two ghosts built into one. He has a big toothy smile and a top hat. Parrying him once will cause him to split into two of the smaller, normal ghosts. You will then need to parry them as well.
Once you have protected the urn for the third and final time, the Legendary Chalice will emerge to gift you the final super, a strange ability that allows you to separate Cuphead’s beefy spirit from his tiny porcelain body. You can then drag him across the arena and smack him into things, dealing damage.