William took the spike at the base of his greatsword and drove it past Knight Leader's defenses and into the right side of his chest.
The spike fitted on the back of the grip wasn't in the same size range as a nail.
Matching the greatsword's full length of 3.5 meters, the spike was practically a stake.
Realistically, even if the attack wasn't instantly fatal, the right ribs must have been pulverized.
[…]
But in truth, there wasn't a single wound on him.
The spike which should have been rooted into his chest hadn't even penetrated the cloth of his suit, let alone draw a single drop of blood.

Toaru Majutsu no Index vol.18 ch.5 pt.9