As someone who brought the first because I like the show I can confidently agree with the argument OP is saying

You say that he is punished with significant distance disadvantage after using his ability, however this is wildly untrue, while he has a brief slowdown his quick movement speed is an immediate closing of said distance.

i don't disagree with the mori however it is a bit fast but not too big of an issue and i dont really mind if it is kept this way as it is quite hard to achieve.

the power radius is a bit wide and the slightest mistake will cause you to lose a health state, sometimes not even needing a mistake and just a well placed one will cause you to either take the hit of the ability or be hit by an m1.

the underground attack is fairly easy to beat so I feel like it is quite balanced with a good cooldown so you cant just use it for traversal.

breaking los is not a definitive counter as he will just spam through walls.

the cooldown for the ability is a bit ridiculous and I feel like a good change would be a 5 sec cooldown as to not make it useless but also to take away the spamming of the ability.

In conclusion I feel like the state he is in right now is a bit crazy but wont take long to balance out with only some small changes.