@Evade-This5965 Ok, this space-time issue is getting serious and I love it. I can imagine instead of the kukri coming back which boomerang, would be "called" between space-time to be thrown again, it must do good damage but it would be the slowest basic of all so that it is not something very op. Yes I thought him had a prosthetic arm but the idea that he is one-armed... I like it much much more. Maybe the spectral arm come only for his super abilities, here is a very elaborate and crazy idea.
What if instead of spectral knives, it is some kind of concentration of quantum energy that only he can see thanks to his glasses (which he also invented) and this energy is what his gadgets use as fuel for his abilities and here comes the best part , that during the Vortex or H & S & D animation this excess energy brings his arm back through space-time. As he does with his kukri in his basic attacks. And at the end of the duration of these super abilities, his arm disappears again. What do you think?
It sounds like something that hides great power and something worthy that big organizations are hunting him for.
I absolutely love the mechanics that @Evade-This5965 describes and also the lore of the wizard façade to hide his identity and the limitations @D4m0R3d describes.
Every reply sounds more and more like a real character with a whole interesting background.