Reborn! –Episode 23 "The Last Dying Will Bullet"

Tsuna is on his way running after Futa, while the others are left to deal with the one claiming to be Mukuro himself. He proves to be too much for them in the state they are in, so all hope lies with Tsuna coming back in time.

The only problem is, even if he does, there is only one Dying Will Bullet left…