I thought I remember reading somewhere that a synthesist's eidolon goes away if he goes to sleep, or something detrimental to that effect, but I can't seem to find the info now. Anyone have any idea if it's possible to sleep in an eidolon suit?
Ah, it's in the Summoner section, no wonder. Curiously, the Synthesist's "Fused Eidolon" section specifically states that "this ability replaces the class’s eidolon ability". So, does that mean a synthesis is fine sleeping with an eidolon suit?
The synthesist archetype specifies that "in all other cases" (meaning those not spelled out in the fused eidolon description) "this ability functions as the normal summoner's eidolon ability".