Reborn Assassin in Classroom of the Elite

As Karma drown himself on his sorrows and ecstasy, he was killed by two killing theives. He of course would win but he didn't expect a suprise attack from behind him. It took time for him to accept it, it be considered as weak and pathetic to be killed easily and it made him have flashbacks with his moments with Koro-sensei. He breath out a sigh before closing his eyes ready to bliss of to either heaven or hell. What he didn't expect is to wake up again in another world where a school just like his, a school with high society of elites but far more than that. Karma himself frown on coming back to school but he can't deny that he'll meet people that can exceed his expectation in the so called elites, mabye find a person who suprises him again with his natural skill other than his best friend Nagisa.

( There won't be any harem since I don't want Karma to be OOC. )