Thanks,
and you're in luck, seems like I kept a save from just before the gauntlet:
Okay attributes:
10str, 58dex, 10mag, 12 cun, 11 will, 24 con (so full dex with a little con to stop knockdown)
Abilities:
dual weapon: everything fully upgraded except backstab (no upgrades)
specialist: speed, precision, power(upgraded), harmony
scoundrel: blindside
swashbuckler: across bow, experienced hand, all hands on deck(upgraded), savvy, sea legs
This isn't the most optimised setup as I was testing out how effective power could be in conjunction with stuns.
The reason why the build was so effective at the gauntlet would probably be more to do with the weapons (including +3 cold from elemental weapons):
Jarvia's Shank: 34physical, +10cold, +26dmg vs demons and undead, +3dex, +7%crit chance, +9%crit dmg
Beraht's Revenge: 34nature, +7nature, +3cold, +61attack, +3%attackspeed, 5% chance to regen health
These weapons meant that I had a base damage of 92 (170dps), with the nature damage doubled against shades etc. I also had lacerate, power and speed running at the same time. In the video I was trying out fel poison (which actually is pretty terrible). If it were possible to speed run it I would recommend just using death root toxin (+9nature as opposed to ~2physical)
I had the poison wood locket (+12%nature), a ****ty ornate belt that gave me 11health and 3% physical, ring of seven watchers (2%crit chance, 4%crit dmg), and most importantly, Lady's choice (2dex, +4%attack speed, +12%damage resistance, immunity to knockback)
This gear wasn't really optimised either (usually don't use isabela so was just mucking around experimenting with her build) but the lady's choice is essential to reducing the amount of constitution you need to get to avoid knockbacks/knockdowns. I think I may have used a rock potion in the vid which also helps in that regard.
Overall she had 206hp, 97%crit chance (=100% after a few hits), 85%crit damage, 22%dmg resistance (10% from potion).
I did an even less optimised gauntlet run based on this build (for my main playthrough without splurging on unneccessary potions/poisons) and it still worked really well - though it was a little slower. The only issue with this build is that it relies quite heavily on dlc, and on your companions locking down enemies (via petrify/crushing prison) and lancing any brittles (so ff can be an issue).
Hope this helps.
I'm sure I could come up with a more optimised build if I needed to. Maybe I'll look into it later for my S&S build (it seems that ff isn't
that much of an issue).
But the key point is to pump as much con as needed to avoid knockbacks/knockdowns then the rest into dex (cunning is not as good at increasing both critical damage and dps).