As far as I can tell so far, the crashing problems are finally fixed... but, I have noticed what I think might be another bug. When saving and quitting under certain circumstances, certain stats are lower or higher than they should be: specifically, stats that are affected by an item that raises/lowers stats by a percentage rather than an absolute value. My Tizik, who fused with the (merged) Crown of Spring, has stats that are all noticeably higher than everyone else, while everyone who had Heavy Shackles (fused or otherwise) has their Speed absolutely crippled despite all the Quickfish I know I've fed them. My guess is that the percentage stat buff/debuff is saved, and then when the game is reloaded, it's applied again, on top of the boost that was already there?
I've seen a similar problem. It doesn't always take saving and quitting, though. Sometimes it happens while going to a new loop. I ended up with the beefiest gheist to ever beef with no food and using the bad fusion. Items had little or no hp bonuses either. Was weird and difficult to try and make him my lowest health since I wanted him to be targeted most.
Another bug/problem I think I might have found is that percentage buffs to healing don't seem to actually be working. I'm not perfect, so it's entirely possible my math was off every time or that I misunderstood something, though. The nature synergy buff, and any item buffs didn't seem to be doing anything though.