[@Xavier Bloodbayne]

Auz gets faster as he dies, strength being a requisite to keep him from falling apart at certain velocities. He is speed based above all else. Auz's acceleration and speed are, to me, superior to Xavier's by a vast quantity. Like I said, it's how competitive balance is achieved due to Xavier having the strength/durability advantage. If Xavier can achieve great speed with a foot, Auz can do far more with a full swing.

Also, Auz's death boost counts suicides as well. He died eight total times so far, the most he can possibly sustain against one opponent.

Starting Auz - 100

First death - 125

Second death - 156

Third death - 195

Fourth death - 243

Fifth death - 304

Sixth death - 380

Seventh death - 475

Eighth death - 593

Each number is multiplied by a flat 1.25 after death.
By your own estimates, this puts Auz's striking strength and speed well above Xavier's.

EDIT:
But, even with all the speed in the world, Auz has pathetic durability and cannot manipulate inertia to build or stop momentum instantly. As such, I fully expect Xavier's initial slash to land, and since Auz is on his last life and far from civilisation, it'll be a mortal wound. 

All that leaves is the question of whether or not Xavier can tank a full-powered Auz slash to the neck. If the sword can chop his skull, I don't see why it can't sever his vertebrae for a true decapitation.