One thing to remember when constructing fight scenes is that the element of the unexpected counts for a lot. I feel like readers might’ve expected Taro to betray the heroes to the crew, but actually getting the upper hand on them in a straight-up fight is probably not how you thought this would go.

Note that Taro is standing mostly out of the highest concentration of “light air” in the last panel. His little spark-striking with Byron here is still a gamble, but he was much less likely to end up burned.

Although that’s relative. The flammability on display here means that “light air” is definitely not helium. Hydrogen works better, though as Phil pointed out, it’s so reactive that the next panel could’ve just been “AND THEN KABOOM EVERYBODY IN THE ENTIRE CHAPTER DIED.” Still, nobody’s going to have any better language for what this element is than “light air,” so I’m comfortable leaving its exact chemical composition ambiguous.