>>34199986>Pex doesn't really do anything to itIf it's life orb then it'll whittle it down pretty quickly.
If it's anything else then it'll whittle it down slowly, set up toxic spikes, and just keep recovering until one of them is forced out from chip damage (Naganadel) or losing too much PP (Toxapex).
Toxapex can heal. Naganadel can't (or at least probably won't, since Roost would be a niche option at best).