I'm not going to commit anything on Gryphon Mountain because no amount of store_unit magic will save us from when the attack event's WML get's processed... I do have a feature request here:
https://savannah.nongnu.org/bugs/index.php?func=detailitem&item_id=12681 hint. hint. :) If nobody else has, I'll look at the -20% experience thingy...
