27 years ago - Uno is born as the champion of the ancient Q society, bred & manipulated to be the perfect man, the avatar of Quetzalcoatl.
3 years ago - 24-year-old Uno finishes his training & departs for America, posing as the deceased Dr. Curt Falconer, first becoming Aztek.
1 year ago - 26-year-old Uno ends his association with the Q society when he discovers that Lex Luthor is one of it's benefactors & joins the Watchtower. He sacrifices himself to stop Maggeddon, fufilling the Q society's prophecies.
Orginal characters have a bit of an uphill climb in the world of DC. Most of their properties are more than half a century old, and even brand new creations only happen by being part of one of those existing properties. Off the top of my head, I can't really think of any brand new character with no connections to existing major properties to be introduced in some time. In that setting, it's actually kind of amazing that Aztek found the sucess he did, even if you're not generally likely to find people who recognize this very innovative addition to the fabric of DC.
Grant Morrison and Mark Millar are a couple of Scottish madmen both fameous for creating utter comic book lunacy, so it's kind of interesting that their creation Aztek is such a cleanly designed, easily understood character. He's a deliberate attempt to craft a new DC legacy, and it reads very easily. If anything, it's only in the panel by panel story detals that you start to see the singular mile-a-minute imagination explosion that makes up the bulk of both men's work.
A member of a secret technologically advanced society that had existed for hundreds of years dedicated to perfecting humanity, Aztel is dedicated to stopping the coming apocalypse. His story ended when his comic was canceled, but he appeared again when he joined Morrison's Justice League. The series-defining threat of Maggeddon turned out to be the apocalypse Aztek had been created to fight, and he sacrificed himself to ensure it's defeat, fufilling the character's purpose. He's a cool character that totally deserves a place in out version of that team.
Of course, Just a minor note about his appearance: There's no reason for this guy to be white. If there's ever been a character that should be latino, it's Aztek.