6* Gully 99 or 6* omega senital

Mentalboy1

Hi, I need some advice. I have recently got cavalier level. Now looking for going further in the game harder modes and poss variants. I need more tech to rank up. With my skill levels I feel may need more 6* due to their health pool. At present tech wise I have 6* R2 ultron who is good. 5* r5 duped warlock don't tend to use him now.
Who out of gully or omega senital would be best to rank 2? Both unfortunately have lower health pools but hit hard and can regen
I've played around with both but can't decide.

Other tech options I have if better than above are
6* R1 silver centurion
6* R1 war hammer
6* R1 red skull duped
5* r4 ghost not duped
5* r4 guardian duped
5* r4 Spidey stark

I do have 2 awakening gems for 5*.

Or should I hold out???

Thanks

KnightOfTheRealm

Omega Sentinel is unquestionably much better than G99. G99 is outdated and I would recommend not ranking her ever.