If Gust targets a small unit (3 or less might) and the unit gets buffed above 3 might in reaction, will Gust fizzle or resolve?

Ruling: Gust will still resolve, but it will not return the unit to hand since the unit no longer meets the targeting criteria. The spell does not fizzle (go to trash without resolving).

Nuances:

• This distinction matters for effects that care about spells resolving, such as Ravenbloom Student
• In Riftbound, spells don't fizzle in the traditional sense - they either resolve, are countered, or are illegal to play (in which case all actions are undone)
• When a spell resolves but its target is no longer valid, it resolves but does nothing (different from fizzling)