This actually doesn't seem all that OP.
Used on an enemy:
It really only hurts having your quanta converted to your mark if you have a duo where your mark is actually the lesser element.
Used on yourself:
This doesn't give you more quanta than you already had.
It only would be a really good strategy if you were using quantum pillars, where this could speed up your quanta production, but
1) It only converts half
2) You would need to have 3
available to use (which could be a problem if you are only using quantum pillars)
Thus, I really do not think this is OP.
If you are really still afraid of it being OP, then I would either remove the quanta production, or turn it into absorption (which I think is completely unnecessary.
