Kiritsugu’s arms, legs, and heart let out sad screams of pain with every swing of the dagger. The adverse effect of Innate Time Control mercilessly tore apart Kiritsugu’s flesh, and Avalon fixed the damage, momentarily. Regardless of how Saber herself had used it, the sheath was only ‘healing’ Kiritsugu while in his body- it could not prevent him from taking damage, it was simply healing the damage he took. The excruciating pain of torn tendons and snapped bones tormented Kiritsugu’s nerves every single moment.

Even so, Kiritsugu did not hesitate. There was no need to hesitate. As long as his body could still move, he didn’t need to pay any attention to what he was feeling. Kiritsugu bet everything on the effects of the holy sword's sheath, and continued to accelerate against the agony.

“Whoaaaaaaaaa!!”

Kiritsugu’s body died and was reborn. He shrieked in agony as he sliced at the enemy before him with the dagger. His blood vessels, endlessly repeating a cycle of rupture and repair, shed sanguineous mists with every movement.

- Fate/Zero: Act 16, Part 6