Not a striking personality?

SCAB

Think of what forms when a wound starts to heal, or what might be called a strikebreaker in labor disputes.

This clue plays on the double meaning of "striking." While it seems to describe someone unremarkable ("not a striking personality"), it’s actually hinting at a "scab"—a term for a worker who crosses a picket line during a labor strike. The wordplay twists "striking" from its usual sense (impressive) to its labor context (a strike), making "scab" the clever answer.