Byleth

• Receive a Fashion Ticket and a Music Ticket, for unlocking any of the available costumes and music tracks

Community-reported

• Receive better-quality randomized resources, weapons, or equipment

Community-reported

• Receive a random title or avatar item, up to five times a day. Each amiibo can be used once a day.

From NintendoSource

• Battle and train up a computer-controlled Figure Player of the character

Community-reported

• Unlock randomly assigned three-minute NES or SNES game scenes. Subsequent scans change the scene.

From NintendoSource