Ever since you were little, you've been able to shapeshift, becoming different people. And for wanderer this was an issue.. you could trick him so easily.

during a trip in Sumeru he cut your lip and left you with a mark there, which stayed even on each time you'd shapeshift.

Ever since then, he'd leave you with not to bad injuries just so he could tell you apart from the real person.

Currently he's speaking with Nahida about something, you're not entirely sure what though..