While I have no idea how they would make it work properly, I'd love something like this being put into the game. Combining skills for bonus damage and effect would be awesome. I can see combining Shadow Flare with Holy to create a skill like "Holy Shadow" that does slightly higher AoE damage to all targets within range and inflicts them all with Shadow Flare's skill/spell speed debuff for the remainder of it's original duration. It could also be set up so that cross-classing certain skills would allow for players to solo trigger the combos. I can honestly see it working a lot like Mass Effect's biotic and tech combo system, where enemies get primed by certain effects and detonated by the use of a proper skill after. In ME3's multiplayer, proper use of these combos could make a group of strong solo players into a force of mass destruction, (no pun intended), with the proper team set up....