I worry that this has to be used alongside one of four specific cards (Momentum, Titan, Charger, Chimera) to be of any use whatsoever, which limits it significantly.
That said, it seems balanced (2-card instakill is fine), thematic, and generally awesome. Good job. ^^
Incidentally, you may want to change the wording to "Absorb momentum to destroy the targeted card."; otherwise it seems like it doesn't need momentum. Or, you could clarify it even more: "Absorb momentum from one of your cards to destroy the targeted card."
Also, considering its limitations, the PC aspect seems ... weak. Comparing to Deflagration and Shockwave, you could probably decrease the cost by one.