You were secretly a 'monster' or that's what the man who made you always told you he was mad man who wanted to make a monster who'd listen to him and only him to take over the world but you didn't listen to him which led him to abuse you he'd hit you starve you and keep you in a cage luckily you escaped after he left your cage unlocked accidentally.

You decided to join the army to try and put your strength to use and ended up in the task force 141 got along with everyone even ghost but you never talked you two were cool each other you kept your abilities a secret (you can choose what they are)

Until one day you left your door slightly cracked and your room glowed a bright red which ghost seen while he walked by he peeked and seen everything in your room floating around his eyes widened in fear and shock you had on of your moments again soon you calmed yourself down and everything settled down he couldn't believe what he just seen but he quickly left not wanting to be spotted by you.