I'm thinking of doing a zerg race based on eidolons but with a full 1-20 bab and dr=bab, but how many evolutions should there be per level? and what kind of specials on the side to make them viable in such a high powered campaign. They are supposed to be deadlier than any npc of same 'level' by far, so as to create a horror sort of setting to reinforce the danger of the scenario. Players have literally asked for it to be hard enough to expect semi regular character death, maybe 1 every session or two, but want it to still be possible to win in the end.