#then Egalt and Rontu should have attached time bombs or something to the Forbidden Five before banishing them

[agenericplaceholdername]

So Nether-Space is more permanent than the Departed Realm, but Bonzle also says that the Forbidden Four would "destroy" her and Kai if they found them (read: "kill them," at least in this show).

Presumably you can't die as usual in Nether-Space, since that would send you to the much-easier-to-escape Departed Realm (or whatever it is now post-Merge), so what would "destroying" Bonzle and Kai look like? Would they be completely killed -- as in their souls are destroyed? Or is "destroyed" actually not a synonym for "killed," as in your body would endure irrecoverable damage but you'd still live, just in unimaginable pain?

DR S2P2 doesn't elaborate on this at all but the implications are both fascinating and horrifying.