Irregular is a energy created by universes converging. It can tear universes apart or keep them together; it is irregular and thus has no real consistency or exact function. It can't be controlled either, but can be channeled. It was introduced in the Mysterious Five Project's Irregular Show as the main driving point for the plot.
Powers of Irregular
Irregular is cable of creating Irregular Clones and Irregular Titans, as well as tear apart universes, open up portals to Anti-Space with ease, hold back Galactus, seam together it's own tears, and can shrug off the Ultimate Nullifier (but not more than one!). It's also cable of creating new universes as seen briefly in Fighters of Lapis 3.
Irregular is in actuality, forces coming from Anti-Space, namely the imaginations of a couple kids as Inori and Chuck D. Head find. Although Irregular had come visible and traceable due to so many universes colliding, Irregular does have a will of it's own, although that will can be channeled, as Dr. Doom did.
- The Irregular Clones were supposed to be color variants for the characters (obviously), but since alternate costumes seemed like it would be too much work, they were used as bosses since CatSerpentine put a lot of work into something that probably wouldn't be added anyway.