Larian Studios Forums Divinity - Original Sin Divinity Original Sin - Beta Alpha Update v1.0.114

Well I would suggest as a combat skill a Stealth that isn't the same as Sneak. With Stealth you would be completely invisible for a turn (or two) and be able to move around the battlefield. Now while in Stealth you would of course have a limited movement (could be offset at higher level Stealth or with using points into a stat). Attacking would of course bring you out of Stealth. And while in Stealth AP usage is higher, with increased damage (possibly) or just higher chance to Backstab, and maybe lower chance to hit while in Stealth (could again be offset at higher level Stealth or with points in a stat).

EDIT: If in range for attack of opportunity while in Stealth and you try to move, there is a chance you will fail and Stealth will be broken, resulting in increased damage for 1 turn.