I completed V3!
I enjoyed this variant, except for the last quest. The magneto bosses were very fun, and I soloed them both! My Favorite fight was the red mags boss, where I had perfect intercepts. The last quest was painful. I eventually brought in some mutants to help get that havok mini down.
-5* R3 Sentinel
-4* R5 G2099
-AA and colossus for the last quest
I had lots of 300-400 hit fights with guilly, as she outdamaged sentinel even with his 100% bonus damage.