ToME: the Tales of Maj'Eyal

sustained spells should be de-activated before registering the quest, otherwise player will auto-fail the quest when the sustains are re-activated upon levelup/stat-change

If it's an illegal sustain, activating it should prevent you from gaining the quest in the first place, right?

I think what they're saying is that you might pick up this talent, use it at low levels, then accept the antimagic quest. At that point, any *more* uses of it will fail the quest, including automatic re-castings at level up.

This is indeed what I mean. Inscribed runes are purged, at least from the hotkey bar, upon receiving the quest, but sustained spells are not cancelled .