Seen that some people, as well as myself, have been playing the Epic Encounters mod for DOS:EE and they have some pretty awesome looking skills which I think would be an asset if they were implemented into Original Sin 2.
Just going to list off a few that I think would fit into OS2 (these are all new to Epic Encounters or reworked older skills), bear in mind that I didn't think these up, that's all down to the creator(s) of Epic Encounters
"Heat Metal": Pyrokinetic. Deals low fire damage and applies warm and heat metal to the target. Heat Metal deals bonus 30-300% damage depending on how heavily armoured the target is. In OS2 terms, the higher the targets physical armour the more fire damage this spell will do (which targets Magic Armour of course)
"Cold Snap": Hydrosophist. Deals moderate water damage which is increased if the target is wet or chilled and increased further if the target is frozen, removes Wet, Chilled, Frozen from the target. In OS2 this would be a solid burst spell when the target has lost all of it's M-Armour (so it can actually be CC'd, still think that skills should have a lower chance of CCing when Armours are up but that's not the point)
"Rime": Hydrosophist. Inflicts Rime on the target which continuously creates 1m of frost below the target (including while moving) while Rime is in effect. An ally will not be slip on the ice while under the effect of RIme. While in OS2 the P-armour would block the knock down effect it would still be an option to halt their advance (Dealing physical armour damage every step if they have physical armour), although most of the melee enemies have Phoenix dive so this skill wouldn't be as useful
"Crush": Warfare. deals 150% weapon damage and applies crush to the target, lowering armour and resistances by X%. In OS2 the damage could be increased against P-Armour (Possibly scaling with the Warfare passive)
Also in the Epic Encounters Mod there are hybrid skills which typically require investment in two ability schools which I think would translate fantastically in OS2 seeing as putting a point in a skill school ability also provides a passive bonus as well as in general just rewarding hybrids more (I am a fan of a good hybrid)
Examples would be;
"Boil": Pyrokinetic, requires Hydrosophist. Deals fire damage and applies warm and boil to the target, Boil deals an additional 150% of the initial damage if the target is either standing in water or wet, if both are true then the additional damage increases to 300%, removes wet and creates a steam cloud around the target. Could pretty much function the same in OS2.
"Cauterize": Pyrokinetic, requires Hydrosophist: Deals fire damage and applies cauterize to the target which removes bleeding and (in an allies case) Decaying touch while healing for a large amount. Same deal in OS2 but of course can synergise with Decaying Touch on an enemy to deal NASTY damage
