Excalibur hax

And so they went eagerly to the battle, and gave many great strokes, but always Arthur's sword bit not like Accolon's sword; but for the most part, every stroke that Accolon gave he wounded sore Arthur, that it was marvel he stood, and always his blood fell from him fast.

When Arthur beheld the ground so sore be-bled he was dismayed, and then he deemed treason that his sword was changed; for his sword bit not steel as it was wont to do, therefore he dreaded him sore to be dead, for ever him seemed that the sword in Accolon's hand was Excalibur, for at every stroke that Accolon struck he drew blood on Arthur.
....

And Sir Accolon lost not a deal of blood, therefore he waxed passing light, and Sir Arthur was passing feeble, and weened verily to have died; but for all that he made countenance as though he might endure, and held Accolon as short as he might. But Accolon was so bold because of Excalibur that he waxed passing hardy.

Le Mort D'Arthur