The main cast obviously focuses on the major Greek gods, but Rick Riordan really shines in how he introduces them through Percy Jackson’s point of view. The comic adaptation of 'The Lightning Thief' gives you Zeus, Poseidon, and Hades right off the bat, but it's the figures like Ares showing up in a leather jacket on a motorcycle that make it feel fresh. The series spends a lot of time on the core twelve Olympians from the Parthenon frieze—you know, Apollo, Artemis, Athena, all that crew.
Honestly, I think the demigods almost steal the show as the real heroes in the narrative sense, though. Percy, Annabeth, and Grover are the ones driving the plot in those first graphic novels. The gods are these powerful, often petty forces they have to navigate. You get a great sense of their personalities visually, like the way Hephaestus is drawn surrounded by intricate machinery in his workshop. The comic format lets you see their divine attributes in a way the novels just describe.
What’s cool is the later volumes start bringing in the more minor deities and Titans as major players. 'The Last Olympian' adaptation has that huge showdown with Kronos, so he becomes a primary antagonist. I’d argue the series makes heroes out of some unexpected figures, like Hestia, who gets a really poignant moment toward the end. The main heroes are the ones fighting for Olympus’s survival, which ends up being a mix of gods, demigods, and even a few loyal satyrs.