The Momentum Talent was, in and out of itself, a very destructive ability. It's something undodgeable and unstoppable too. Because it is the result of the opponent's attack being reversed and thrown at them, it's not something that could be physically manipulated.
Hell, except for changing the direction, Kai can't control the Momentum either. He can't decrease or increase the effect, he also can't stop its glaring downside. Apart from the huge amount of Origin needed to execute it, the talent also affects the user as much as it affects the target.
'Tsk…' Cursing inwardly, Kai felt the pain from the impact attack hit him right in the face. Even when reversing the attack's momentum, Kai still would feel the direct pain from the hit on his body.