Maybe a higher cost on both the ability and the actual weapon cost, also less damage (10 is too OP for a weapon, and perhaps for unupped destroying it should be less damage, maybe 7-9 damage?)
Titan does 7 / 8 damage and has similar cost with no downside... and it bypasses shields to boot.
Also, Fahrenheit regularly does far more than 10 damage (up in the 20s at max
if I recall) and has an even lower cost.
The ability cost is on par with steal I think
I think raising the casting and ability cost is reasonable, but I'm leery about dropping the damage too much or else it will become UP.
Raising the cost might be reasonable but I think it should do more damage than titan.