Can you cast Void Assault targeting a unit that has been stunned by Vex, Apathetic and is restricted from moving?

Ruling: Yes, you can cast Void Assault targeting a unit that cannot move due to Vex, Apathetic's "can't move it this turn" restriction. The unit is still a legal target as it meets the targeting requirement of being a friendly unit. At resolution, the first move instruction fails due to the movement restriction, but under DAMAYC (Do As Much As You Can), the second instruction to move an enemy unit still resolves normally since it is an independent instruction that does not reference the first move.

Sequence:

• Cast Void Assault, targeting the restricted friendly unit and an enemy unit (such as Vex)
• At resolution, the first move instruction is ignored because the unit can't be moved
• The second move instruction executes independently, moving the enemy unit

Nuances:

• The two move instructions in Void Assault are not linked instructions under Rule 359.3.e.14, as the second does not reference any Game Object or Game Action from the first
• Vex's "can't move" restriction is absolute and prevents movement by any means
• The unit must still be a valid target when casting (a friendly unit exists), but the instruction does not need to be executable at resolution