Guardians, BF, Elder Wraiths' "glitched" KB intentional?

^
On that topic, what about Pink Bean (Weak)? I'm pretty sure you can't hit PB during Phase 1-5.

Edit: Also, an inactivated statue (ie Ariel during most of the battle), or a previously "killed" statue before Phase 5 (like Huigin or w/e after it's stopped but before the start of the next phase)

Those are monsters that die but don't leave the map, or just flat out have no hitboxes. This is different, these are monsters that lose hitboxes during special periods as an ability.