Uh... What do you mean by 'Roleplay' in the context of this being a Minecraft forum? Is this going to be for a server, where people play together as their characters, or for a story you'll make into a Ben 10 map? I honestly have no clue. But for the fun of it, I'll just fill out your character sheet thing.
Name: Merry P. Ipen(Ih-pen).
Species: Human/Mechamorph hybrid.
Powers/weapons: Technokinesis, minor shape-shifting, eye-lasers, and a Prototool.
Omnitrix Aliens: None.
Backstory: Make up whatever you want.
Personality: Same a one above.
Appearance: Caucasian skin, black hair, green eyes, black T-shirt, blue jeans, and black and white sneakers.
Eh, maybe you shouldn't have master control, not yet anyway. It's too OP to just have the hero have it in the beginning. Just start out with, say, eleven aliens that all have Ultimate forms? I'm sure you can think of something. But for now, just wait until after your character talks to Azmuth, or starts messing with his watch, but even then, maybe have it be for one episode, like they did in the original series. 17 is still too young to have master control. "Maybe for your 18th birthday."
My character? Eh, not much too tell. He's super smart, can control technology and 'talk' to it, can fire lasers from his eyes, and has a homemade prototool(Not quite as good as Rook's though.) On the flipside, he's vulnerable to strong magnetic fields(Gives him a serious headache), has a narcissistic attitude, isn't very physically strong, and doesn't play well with others. He's the child of a rogue mechamorph that illegally migrated to earth. Let's see, what else... Eh, I'll think of something later.
"Well that was a total waste of time" He muttered while entering in the Plumber Base. He just was on a mission of a week to capture a alien and is was boring, but at least is wasn't really a total waste of time, after all he got a new alien(Now he have 15 aliens).
"Yes, it was quite dull. But you did manage to break your record of how long it takes to beat a villain up while destroying a lot of stuff." A cynnical fourteen-year-old replied to his friends moaning. "Honestly, I don't know why they bothered pairing me up with you." Okay, 'friend' was a bit of a stretch of the word.
"Why we were even assigned to this mission together?You aren't so good at finding invisible things" He asked his ,,friend'' ,annoyed by his reply. (I thought to make my character weaker to can't have him change from a form to other or to give him a random one when he try and i shoul scan your DNA? :p)
"Hey, you try finding cloaked artifacts when a manna overload throws off your scanners!" As they were bickering with each other, they walked into the Plumber command room. Magister Max Tennyson turned around at the sound of their argument, and sent them both a small glare.
"Can you two please try and get along for once? Fighting between ourselves won't solve anything." (To make your character weaker, I'd say to go with the random form-to-form switch. And no, no scanning of Merry's DNA. Let's just say that it already has the sample of Mechamorph DNA in it's database, and since your character is human, it doesn't need the other half.)
Merry raised his eyebrow at this. "Only if you're ready to lose." He emphasized this by igniting part of his skin in a circuit pattern a bright neon green. "That is, if we don't have any other assignments?" He said, looking quizzically at the Magister.