Although there are many skills to the same function, but also almost all of the skills in 12Sky2, found a slight difference. Moving AoEs are now stationary, for example, and level(Twelvesky2 powerleveling) 60 attack skills are much rarer drops. Largely though, the differences are cosmetic: there are still single hit, multi hit, and area attacks for each weapon but their animations have been updated.
Rare items(12sky2 Gold) have new glow colors: up to 57% glow Green, 60%+ is blue, 9x% is purple. A few things have been altered. Uniques now benefit more from enchantment, and also glow if they have been enchanted. Items can also now be enchanted up to 60% safely, but items 60% and over risk breaking during enchantment. Combining has changed very little, but Upgrading as well as Downgrading are now performed with Jades (Red/Purple).