:D seems like they put the old multiplicative formula back because of Zombo Invasion.. (?)
thank you, Brainz(epic mats).. for not showing up with additive formula.
(and also ty Jupp, just realized you put a lot of thoughts to seems-like-a-simple-game)
iirc, before the new zone/raid were released, the difficulty of previous zone were reduced.. (or was it after?), just for reminder, because haven't seen any of it in the patch notes. :/