Unlock: Complete Friends Reunited, Use Trevor
Bonus Requirements:
Fist Fury – Receive zero damage during the Willy fight.
Entourage – Talk to the entourage members.
Go to North Vinewood and find club "Tequi-la-la". Enter it and you can find Willy talking to someone. Do not talk to him yet, just go upstairs and chat with his bandmates to acquire the bonus. Now go back downstairs and beat Willie to a pulp. Grab his golden teeth and exit out asap.
The image featured at the top of this post is ©The Legend of Heroes: Trails of Cold Steel III key art.