Katekyou Hitman Reborn!

Synopsis

Daemon Spade reveals that he had been controlling Chrome to draw them out and tells Tsuna and his friends that he will now be testing them all on his own terms in order to turn them into his idea version of the Vongola Family. Tsuna and his friends enter the building and are then separated and confronted by a dark version of themselves created by Daemon. While the dark versions gain the upper hand, Daemon tells Yamamoto that he must kill his double, while simultaneously tells Ryohei to be merciless in battle and abandon Lambo in order to win, and taunts Tsuna and Gokudera that Tsuna is not worth to be protected.

(Source: Wikipedia)