I try to keep the world and story of Aios interesting outside of fights and set-piece moments, but I'm still a sucker for epic battles.

Probably the one that tops it all off comes after fifteen to twenty years of the main arc, and following some of the hardest times of the modern world.

The continent of Eurona was lost to the Steelskin - a biometallic assimilating collective (think T-1000 meets the Flood) that had terraformed the isolated landmass and made it their home - centuries ago. An orbital ring supporting tremendous solar power arrays was appropriated into a solar laser weapon to burn the Steelskin out. They responded, before they could be fired upon, by slicing the ring itself apart with a mountain-sized fusion cannon. While other methods of power generation existed, this crippled the dominant source.

Following this a black fog emerged from places unknown, that behaved semi-sentiently and would consume those possessing magic that it was able to envelop. Originally this just meant sealing oneself in appropriately warded locations, but the Miasma learned tricks as it grew, such as to hide in the folds of people's clothes or even in their lungs to be carried in to 'secure' locations. Many people moved to occupy underwater and/or submersible vehicles and habitats. The massive influx of people into the oceans blew up existing tensions between the leviathans, kicking of events that would lead to their dwindling into extinction. About 600 million of Aios' 5 billion people were consumed by the Miasms before it was stopped.

Later, we learn the arrival of the Steelskin on Aios was not a fluke, but rather it was the vanguard of a much larger force claiming entire systems and galaxies. The planet-bound contingent launched the sizeable collection of rockets once abandoned in Eurona to wreak havoc and seed infection sites across the world, which the extraterrestrial faction could take advantage of. The 'good guys' have to race a shadow government's elites to the heart of the world to activate a purging mechanism. They succeed, however the Steelskin station themselves on the nearest body - the red moon - and begin digging.

The man who gave the world magic sought to keep that gift limited to a select few he could influence. He was able to be stopped, but not killed. Instead, he was drained of his magic blood, the Titan he built to quash all resistance was buried deep, and he was imprisoned in an asteroid that was passing by. He takes control of a great guardian - another Titan - that was watching over his cell, and uses his magic to rework the moon into a weapon to destroy Aios. The good guys, in their quest to re-establish the ancient monarchies of the world, are able to take the parts of a third Titan they each possessed, and confront the released big bad with it. He, however, calls upon the original, buried Titan to come to his aid.

The final conflict in the entire four/five book arc is the core team of seven fighting in a reassembled giant robot against two others. Yes it's basically Voltron, fuck you I like it. Imagine the final battles of Pacific Rim and Gurren Lagann mixed into one.