Which skills use both hands, and how?

As I’ve played the Nightblade class, I noticed that Shadow Strike does damage from both hands while dual wielding. It also seems to deal the listed Cold and Pierce damage twice over, once for each hand.

Anyway, I looked but I can’t find a list of skills that use both hands. Is there one anywhere?
And, of the skills that do, which ones also double the skill’s base damage? Or do all of them double it?

All Nightblade WPS skills (top line with %% to proc) use both hands and Shadow Strike as well.
Blitz in Soldier’s tree uses both weapon and shield but not 2 weapons as far as I know.
Usually you can see corresponding skills by descripton while dual-wielding. Exception is Cadence - it uses only 1 hand, chosen randomly but there’s a chance (50%) that you also hit with other hand but w/o Cadence’s whooping bonus dmg.

All flat dmg (like those you see in Shadow Strike and also given by skills like Lethal Assault, Dual Blades, Deadly Momentum (Soldier), Fire Strike (Demolitionist), etc) dealt twice if the skill uses both weapons.
Amarasta’s Quick Cut deal tripple flat damage as it counts as 3 hits as far as I know (someone correct me if I’m wrong).