Most of the other powers that Samarai randomly display can probably be explained as corollaries of his basic "air elemental" abilities. He occasionally turns invisible, but that could be thought of as turning his body to a gaseous state. Even his occasional random ability to set things on fire could be explained as the result of his control of oxidation.
His origin... a professor empowered by a beam of energy sent by the New Gods... always reminded me a bit of Doctor Light.
Ooh, that's some good thinking EDE! I love the idea of making his random grab-bag of powers instead all based on air manipulation or taking on properties of air.
With a little comic-book Treknobabble, even the illusions could have something to do with refraction and whatever, like how heat in the desert can ripple the air and create mirages.
Concentrating oxygen in the air around a certain point could cause it to spontaneously burst into flames, so that one totally works (according to my hasty Googling, since my high school science classes ill-prepared me for this conversation).
Invisibility shouldn't be much of a deal for someone who can, at least partially, turn into air, since air is generally invisible to the human eye (although he would likely also be intangible as air in that form as well).