Arbalest, Arm Slave ARX-7

Flash, indestructible, reach, mount 3
Reduce the cost of Arbalest, Arm Slave ARX-7 by {1} for each creature you control.
{7}, {t}: If you control Sousuke Sagara, MITHRIL, choose one --
- Deal X damage to any target, where X is Arbalest's power.
- Prevent X damage that would be dealt by target source, where X is Arbalest's power.