How he did not break his legs?

Because the way he landed took off the pressure. He bent his knees and rolled.

I wanna say assassin's creed

There is a correct way to land from heights that will significantly protect you from injury. If he was too much higher it probably wouldn't have been enough though.

Elementary my dear Watson

He sacrificed an extra goat to Satan.

He looks like he's going to have a bad case of whiplash.

Transfer of energy in that roll. Or just simply editted. One or the other.

He rolled so the force of the fall was convertedfro vertical to horizontal. Then he could just roll until the built up force dissipated.