I've recently been soloing FSC over and over just to get some practice and quick money, and I've gotten so good at it that my Combuster and Final Flourish combination can kick so much ass, my one-bar connection doesn't really matter anymore. So I was thinking for something less monotonous to do, and I thought of using nothing but Autoguns. How viable would this be?
Armor and trinkets:
Shadowsun Stetson
Nameless Poncho
Swiftstrike Buckler
1 Elite Handgun Focus Module, 1 Elite Trueshot Module
Normal, elemental, shadow defense; freeze and poison resist (though this isn't relevant in Firestorm Citadel); ASI ultra, CTR very high, DMG very high
Weapons:
Blitz Needle (main weapon)
Plague Needle (for poisoning Vanaduke)
Volcanic Pepperbox (for handy knockback in tight spaces such as FSC D27's last room, as well as Vanaduke's mask)
When I do FSC, I use Blitz almost exclusively already, so auto gun only isn't much of a stretch. Just make sure you have decent ASI and CTR.
That said, I only have Blitz. Although I have heard bad things about the other two.