When Fiora is defending alone 1v1 with Master Yi as your legend, in what order do their effects apply, and what happens if another unit joins the combat?

Ruling: Master Yi's passive +2 Might applies first, then Fiora's triggered ability doubles her total Might. The doubling snapshots her current Might value when it resolves.

Sequence:

• Yi's passive +2 Might applies (Fiora goes from 4 to 6 Might)
• Fiora's trigger resolves, doubling her current Might (6 becomes 12)
• If another unit joins after the trigger resolves, Yi's passive is lost but Fiora keeps the doubled value
• When combat ends, Fiora returns to base Might

Nuances:

• If a unit joins combat after Fiora's trigger has resolved, she loses Yi's +2 passive but keeps the doubled Might value that was calculated when the trigger resolved (resulting in 8 Might total: base 4 + snapshot of 4 from doubling)
• Fiora's "this combat" duration lasts through the end of combat, including when units heal and attacker/defender designations are removed, so she won't die from marked damage while still having doubled Might
• If a unit joins combat before Fiora's trigger resolves, the trigger still doubles her Might even though she's no longer in a 1v1