A nitroverse is composed of 99.9% nitrogen. It's one of the rarest verses. Nitroverses also have Nitrogen Stars that are made up of 99% nitrogen, 0.9% iron and nickel. The rest 0.1% are gasses and noble gasses. Nitroverses are rare, because after 1 trillion years, they become Ironverses.
They also have giant molecules that can be as big as 50 kilometers, made only from nitrogen. These can be turned into millions of N2 molecules.
The Ironverses are the Nitroverses that are older than 1 trillion years and cooled down to -273.15 Celcius, they are made of pure iron.