If Annie with Cleave (granting Assault 3 until end of turn) attacks one battlefield, drops back to base might after combat, then is moved via Ride the Wind to another occupied battlefield, does she gain the +3 might again?

Ruling: Yes, Annie will gain +3 might again at the second battlefield. Cleave grants Assault 3 until end of turn, and Assault gives +3 might while the unit is an attacker.

Sequence:

• Annie attacks first battlefield with Assault 3, gaining +3 might (3→6)
• After combat ends, she loses the +3 might because she's no longer an attacker (6→3)
• Ride the Wind moves her to another occupied battlefield
• She becomes an attacker again and gains +3 might because she still has Assault 3 for the turn (3→6)

Nuances:

• The Assault keyword is retained until end of turn, but the might bonus only applies while the unit is actively an attacker
• The might bonus can apply multiple times in one turn if the unit becomes an attacker multiple times