If Master Yi is defending with another unit and that unit dies during showdown, does Yi's passive activate when he becomes the only defender?

Ruling: Yes, Master Yi's passive activates after the other unit dies during showdown, once he becomes the only defender.

Nuances:

• Master Yi's passive is a passive effect that is active at all times when conditions are met (defending and alone)
• The passive checks continuously, so it activates as soon as the conditions are satisfied