Gammaverse

(also known as γ-Verse or Other Intellectual Properties)

Essentially, Gammaverse serves as the "Crossover Realm", providing a means of contact between the inhabitants of Sinon and characters from other intellectual properties. The parts of those other IPs that are used in this way become parts of Gammaverse. As these stories amount to crossover fan-fiction, they cannot be considered canon, and must remain "behind the scenes" chapters.

Nexus Adventures
Here are some of the Gammaverse stories played out by ZTG devs.

World of Blades (WOB)
Zetoshin and Thanatos track down a rampaging, greatsword-wielding universe-hopper, crossing dimensions until arriving at the mysterious World of Blades - A small planetoid dotted with innumerable swords, all enchanted to prevent their removal from the global battlefield. Zetoshin eats a car. Maybe. Swords and characters from all over late 1990's RPG and anime fandom are included.

Xenogears Recrudesce (XGR)
Zetoshin finds himself living out the all-too-familiar events of the old PSX JRPG Xenogears, but with a twist - things aren't happening exactly as he remembers them! Onizeto makes his first appearance outside the Nexus, causing no end of trouble for his counterpart. Eventually Zetoshin eats the Zohar, and Onizeto merges with Deus.

Save The Universe, Save The World (STU)
A multi-part adventure that starts with Zetoshin getting attacked by a crappy knockoff of Kadaj from Final Fantasy VII: Advent Children. After talking to Thanatos about it at the Nexus, the pair decide to track down and kill the real Kadaj, so people will stop playing as cheap knockoffs of him. Their adventure leads them through a messed up Final Fantasy VII timeline, takes a detour through Dragonball Z, and has no canon ending.

Fear and Loathing in New Alcatraz (FaLiNA)
An Arroyan merchant prince and a young, untested Yautja awaken together in a strange prison, on a strange asteroid, in the middle of deep space. They must escape together, avoid capture, and figure out not only where they are, but how to get back to their mutual homes.

Wanted: Dead and Alive (WDA)
Xylinia and Mezzo make fun of Disney's latest IP acquisitions as they rampage across "Kingdom Hearts 2.X" in search of an alternate version of Mezzo. Currently in progress.

Trivia

 * In Gammaverse, August 5th 2219 is the date given at the start of Stages 2 through 4 in the PS1 shoot-em-up Raystorm.
 * Gammaverse will probably be the best Verse in Sinon, once it has Mezzo in it.