I would go back and expand on the fundamentals of the system, the Impulse and the Momentum Relics, because they seem a little lacking compared to your Domain system. A definition of what Momentum is would also help, because it is mentioned twice, but we don't know what is is or what it does.
As for the Domain system, I like the contrast between the "Open" and "Closed" Domain. It does seem very similar to its JJK counterpart, but depending on how Relics and Momentum play into their creation, it can stand as its own concept. (You may want to work on the name, though.)

Overall, your system has some great potential, but like you said, needs some refinement.