Tom Strong is the main character this issue, the third in the series, Tom Strong, and the first issue where he is that main character. Moore even does a bunch of first person narration, which gives the reader the first insight into him.
The story is fairly straightforward (especially for a Tom Strong). Aztecs from another dimension are about to take over the planet and it’s up to Tom Strong to save the world. And he does, of course. Moore presents him as a very thoughtful protagonist—this issue is an example of some of the best first person comic book narration. Moore’s not using it as exposition (he opens with some funny expository dialogue though). He’s just plain writing.
This issue reveals the series to be mildly didactic. Well, at least the last two issues. Moore’s Tom Strong is intensely, thoughtfully optimistic and it strives to share that outlook.