Caster Bully Mag -
This build works super well for a magnetize -> polarize [Mag], adding in breach surge to amplify damage even further.
It all synergizes super well to allow you to 1 shot anything that enters your bubble. Set up in a room, and go off. Pick a target to magnetize and run through -> Breach surge -> polarize. Definitely use [Magnetized Discharge] for the larger bubble, as it helps a lot.
When shields get low, use polarize to get them back and reset shieldgating. [Natural Talent] really helps with that. [Primed Sure Footed] is in here because if you get knocked you get dead. Replace with [Handspring] or [Power Drift] if you need another option. ([Handspring] for more defensive, cause [Power Drift]'s 30% chance to resist is 70% chance to die)
I also really recommend leaving the mixed build. It lets you shut down entire corridors/chokes with your magnetize bubble, any enemies that enter will get deleted.
Nullifiers are the only real "counter" here, but if you use shieldgating to enter their bubble and take them out, you can then cast freely again.
psa: Crush is a decent CC, but overall not super useful in this build. Use it for a quick AOE CC to knock enemies off their feet, but breach surge is a faster & more synergistic option.
If you have questions, feel free to stop by a stream! https://www.twitch.tv/severedsanity