If Leona stuns Yasuo, does his ability damage still happen?

Ruling: Yasuo's ability damage still happens when stunned because stun only prevents combat damage, not ability triggers. However, Yasuo's ability only triggers when he is attacking, so if Leona is attacking (stunning) him, he would be defending and his ability would not activate.

Nuances:

• Stun prevents combat damage but not ability triggers
• Yasuo's ability only activates when he is the attacker, not when defending
• If Leona attacks and stuns Yasuo, he is defending and his ability doesn't trigger regardless of the stun