How does Convergent Mutation interact with Ahri Legend ability during combat?

Ruling: When Ahri's Legend ability triggers and goes on the chain, an opponent can play Convergent Mutation as a Reaction before Ahri's ability resolves, allowing the unit to gain might equal to another friendly unit before receiving the -1 Might from Ahri. If Convergent Mutation is played after Ahri's ability has resolved, the unit will still gain might until it equals another friendly unit, regardless of the -1 Might effect already applied.

Sequence:

• Ahri's Legend ability triggers when opponent attacks a Battlefield she controls and goes on the chain
• Opponent can react with Convergent Mutation before Ahri's ability resolves
• If played as a Reaction: unit gains might first, then receives -1 Might from Ahri
• If played after Ahri resolves: unit gains might to match another friendly unit despite having -1 Might effect

Nuances:

• Convergent Mutation has the Reaction keyword, allowing it to be played in response to Ahri's triggered ability on the chain