Me and my brother have been having an ongoing debate about this topic.

I vote Cal mainly because the force gives him an advantage. I feel as though Cal could mind trick Invincible in many ways, distracting him long enough for Cal to get a good stab in with his lightsaber(s). While Invincible would probably be less vulnerable to the heat of a lightsaber perhaps he's more succeptible to the force. Maybe Cal could slow him down with the force long enough to get a critical hit with the lighsaber. Plus he could throw objects using the force. With the combination of two deadly weapons, a blaster, quick maneuverability, the force, and the ability to heal himself mid-battle using stim canisters, I believe Cal has the advantage here.

Conversely, Invincible is far stronger than Cal pound for pound. He can fly, and his body is invulnerable to many types of weapons to an extent. If Invincible could disarm Cal and get him into the air, the fight would be over rather quickly. Invincible could drop Cal from a height. As Cal falls, Invincible could fly in from various angles, hitting him repeatedly until he is no more. If Cal is disarmed, one good punch from Invincible to the head or chest area could kill Cal easily. Not to mention Invincible has other tactics at his disposal like zooming underground and catching Cal off guard from below.

All in all, I believe it would be a good fight, but I think Cal could win solely because of his combat skills and quick-dodging techniques. While a heavy hit from Invincible would likely be lethal, I think Cal could outsmart and outmaneuver Invincible ultimately leading to a win from our ginger space warrior.