My far out 100% untrue theory is that Gale is actually a de powered Khelben Arunsun (aka Blackstaff)
I mean he did hint at recognizing Shadowheart’s “secret” Shar worship. Shar is using him to rebuild her shadow weave and Mystra left him because he was seduced by her BFF Shar. That little orb of magic will end up not being weave at all, but a sliver of shadow weave that jump time….
