He completely transformed into a confident person.
Tips
memory
Core words: 蜕皮 (to shed skin) and 蜕变 (to transform). Picture a cicada leaving its old shell behind — that image powers both the literal 'molt' and the figurative 'profound change' senses.
Right side 兑 gives the sound (duì shifting to tuì) and a fitting flavor: 兑 means 'to exchange', and molting swaps an old skin for a new one. Same phonetic in 脱 and 锐.
