How does Draven not cut himself?

He's Draaaven. He's too badass to care about little things like physics.

In game he holds them out away from his body and holds them with the ring facing outwards.

In that picture, he loses an arm.

Who needs arms and physics when you have swag.

That's the point of the weapon. Draven is intentionally using something no sensible person would ever use because he wants to show off.

his skin is too thick to be cut.