In this universe, an extremely plausible turn of events is to have them create a
nothlit human form. Their abilities might have been useful on occasion, but the conceit in Rogue Element is that they are now too sick to even try it. In a way, their condition has become a running implication/joke about my improving skill as a writer.
Myitt sees their abilities at the peak of their health, when I first meet Tara in the early young stupid teenage years. When we come to the Bar and Mar and I try our hand at multi-player Roleplay, they're starting to get sick enough that using that power does more than just wear them out. By the time Rogue Element comes around, our skill level and the dictates of the universe demand that they're actually sickly by this point.
As for Ossanlin, since it's more or less indicated by the characters that everything in the Bar and the extra-board Roleplays actually happened....that means he really was that absurdly powerful. There are two possible explanations then for the power loss:
(1). Ossanlin's decided, as you mentioned, that using his powers is too crazy and risky after the last couple rounds.
(2). He is only that powerful in the Galaxy's Edge Space Bar. In the Bar, space and time were so ridiculously broken that a shard of the Devil, a being without a body, could manifest in a nearly human, physical form. Myitt's bizarre Mar-escapades are otherwise implied to happen either only in her mind or in a temporary reality distortion. Basically, it could be that the place allows Ossanlin access to a great deal more power than he actually has, of multiple or differing Ossanlins.
....love theories like this.
