The Regret Academy's Unretired Hero

After years enduring a hellish 'exile' fantasy, sacrificing everything to escape, I found myself in a different kind of nightmare: a 'regret trope.' The twist? I possessed the body of Baek Yushin, a bullied high schooler, infamous for being a 'loser' at a modern Hero Academy. To cope, I feigned amnesia. Now, everyone who once tormented him is rushing to make amends, including his fiercely devoted (and slightly delusional) sister. They believe they're healing a trauma victim. What they don't know is the true trauma I endured made me a ruthless, pragmatic veteran of countless battles. The original Baek Yushin might have been a pushover, but I'm a hero who never truly retired. Their 'remorse' will be their downfall, because the only thing I've forgotten is how to be merciful.