Posted November 05, 2019

Basically, the way it works in MM2 is like this:
* When you rest, your maximum HP will be reduced to half its normal value. (Don't panic! This HP loss is not permanent, and does not get worse over multiple rests.)
* Curing poison via spell won't immediately give you your HP back. However, if you rest afterwords, your maximum HP will return to normal.
* In MM2, curing poison (or anything else, for that matter) at the temple immediately rests the character, returning the character's maximum HP (and also removing temporary effects that boost stats, including the bonus from Max HP potions).
(In most CRPGs, poison is damage over time; the one other non-standard handling of poison I've seen is in Phantasy Star 3, where it prevents healing (but not resurrection with full HP) until cured.)