I found my end in the gloomy stables... Is every building supposed to have a quest page, and is it always on the last floor? I couldn't find one in Gloomy Stables, and floor 5 is just too bonkers to roam around, even though I was abusing what I believe is a bug (see below).
I think there might be a bug with damage calculation that leads to sometimes gaining one type of life while losing another. Once I got this +4/+2 samurai armor, I started noticing my Spirit increase when fighting some E's. Perhaps a max(0, damage) check is missing?
