My main pick is a warlock. The lower level armbands are honestly not that great, but later they get more flashy and a little more high profile. Holograms, designs, ect. Though, I'll admit, I've seen some good ideas on here. I like the gauntlet on the right hand, big, bold, lots of space to work with. Go to darksiders, check Death and War's gauntlets out. I also like the idea of the pauldron, but it seems like too much armor to me. You start bringing over into Hunter and Titan territory. The easiest to add, would be particle effects. Like bands of magic or lights that follow or trace or movements, maybe effect light ability colors.