I don't think superbolide needs a change, but the GNB kit could get a bit of help.
DRK has a sustain close to GNB but also has the strongest mitigations thanks to TBN and Dark Mind, on top of Living Dead, arguably the best invuln.

GNB defensive kit is very solid but I feel that Camouflage and Aurora aren't doing a very good job.

Aurora is basically Equilibrium but it trades 1000 healing potency for a charge.
Either buff its potency or give it a side effect, it could even have an Excog effect, making GNB the "excog tank".

Camouflage is free mitig but when you compare it to other 90s mitigation...
Bulwark blocks all incoming attacks, which is a 20% mitigation.
Thrill of battle is 20% extra HP, it's not exactly 20% mitigation but it's still good with other mitigations, prevents you from falling low.

Then Camouflage, 10 more seconds but half the effect (10% mitigation) and 50% chance of parry.
It's not worthless but the parry is random and only works on physical attack. Which are more likely to be auto attacks.
I feel like Camouflage could trade its parry for something else entirely.