When Jenos catch you with Void Grip, you only need to use your poppy bomb, (for this situations you should go Jolt) then you have to escape as quickly as you can, if he goes The Power of Cosmeum, doesn't matter, you are inmune to Crowd Control.

Void Grip makes him an easy target for your team, although it also leaves you vulnerable to his Grumpy Bomb. Void Grip him when you can quickly escape behind a wall so he or his allies don't punish your open defenses.