I just saw a game where the guy faded his opponent's Utterdark Spectre, yet other incorporeal champs still stealthed.
Not sure why it would unstealth the other champions. The ability reads "At the end of your turn Incorpreal champions become stealthed" not "Incorpreal champions are stealthed". Once the champion is stealthed it has the stealthed condition and should stay stealthed until it gets detected or destealthed for other reasons.
Just my idea, but FR probably deserves a change due to the amount of glitches it may cause. I would be ok for it to cause confusion and some other condition (defiled?). Was the problem with the permanece of abilities granted by other abilities solved?
Chances are that insubstantiate isn't coded as an ability per se, but an innate part Utterdark Spectre somehow. Either that or FR ignores it for some reason. @Sokolov Oh, another option is insubstantiate only makes a check for Utterdark Spectre in play and ignores the fact that it may no longer be on it.
If FR removing an ability causes an issue, the issue is not FR, but the ability, and losing the ability in EVERY OTHER CONTEXT would do the same thing.
Confirmed. Insub is a really old ability, and what appears to be happening is that the effect is code to remove itself only when the champion DIES, not when the ability is lost. The same thing occurs if the champion becomes Confused.