Nitrogen (Nitro for short), as small as he may be, is actually the MPA’s skilled mechanic. Not only can he build machines used for transportation, he pilots them as well! He’s always ready and willing to transport Hydrogen and his friends to and from missions with his custom-built Chinook helicopter. He’s also skilled at making customized vehicles and tools for MPA agents, such as Hydro’s hoverbike, Helium’s umbrella-gun, and Potassium’s waterproof armor! As a hobby, Nitrogen collects knowledge and facts about every member and sector of the MPA, and especially freaks out whenever he meets a veteran or visits a secret room which only a few know about.
Nitro is the last playable character in the series, and you can unlock him towards the end of the second arc, Atomic Vengeance. He wields a wrench that he can use as a club to whack enemies with, but with the shortest amount of health out of all the other characters, he’ll find it tough to stay alive on the battlefield on his own. But that won’t be a problem! Nitrogen has the ability to use the remains of defeated metal enemies (and there will be a lot of metal enemies) to build a suit of armor like the one on the left that not only protects him from harm, but also increases his moveset drastically! Without armor, he can only swing his wrench once before regaining his balance. But with the armor, he can string together combos thanks to the added strength and stamina!
The type of armor depends on the type of material. Some material can even be used to build a small helicopter to get to hard-to-reach places other characters can’t get to, or a mini-submarine for easier underwater travel! However, if the armor takes too many hits, it will break apart, and Nitro will revert back to how he was before.