User blog comment:Xilinoc/Ch. 636 - Sensitive Monster/@comment-26091912-20150724015302

Oh goody, looks like Pernida will be spamming The Compulsory ad infintum for another few chapters.

There seems to be variations of The Compulsory depending on what's being "compressed"; if you recall in the earlier chapters, Pernida used it in a different manner on the giant Soldier, and mangled part of the cage of trees by "inflating" them. When Pernida used it on Kenpachi, it looks like Blut Vene extending outside the body, but Mayuri said its ability isn't linked to its main body.

Since Gremmy is a brain inside a protective casing, would it be far-fetched to suggest that Pernida is a nucleus inside a pseudo body made of Reishi?