High player skill frames, builds, or playstyles

What are your recommendations? I'm looking to challenge myself. For instance, right now I'm trying out a speed volt with all survivability via manual shield gate. I also always use a primary that I need to aim, which is extra challenging at volt speeds.

I was really hoping I could get a non-cataclysm (solo) limbo working, but everything I tried just seems too clunky.

Any other frames, builds, playstyles that you'd recommend? thanks