If Yasuo Remorseful enters the battlefield for a showdown and activates its effect, but is killed in reaction, does he still deal the ability damage?

Ruling: Yasuo Remorseful will not deal any damage if killed in reaction to his ability triggering, because he is no longer on the battlefield when the ability resolves.

Nuances:

• The card has "here" text, meaning it must be on the battlefield when the ability resolves
• When killed, Yasuo moves to the trash before his ability resolves
• Since he's not "here" (on the battlefield), the ability does not deal damage