I don't have a perfect story, but I did create my own character in the Marvel universe just last night actually. Definitely not finished but here is the majority of it:
Name: Tame. He picked up the name from a group of hunters that were in the rainforest he grew up/lived in. The poachers were on an illegal Jaguar hunt when they were chased away from their kill by a wild human. The main poacher yelled out "Tame that man!" as he fled. So the first word that was ever said to my character, Tame, is his name.
Parents Unknown (for now)
Background: Raised in the Amazon rainforest by literal animals in a forest so he has animal like traits (reflexes, agility, raw power, etc.). How he ended up in the Amazon rainforest is a mystery that will be solved in a later arc (haven't come up with it yet.)
Powers: -Can channel and hone in on one specific animal to gain more access to their corresponding traits; jaguar=speed/stealth, Howler Monkey= Intelligence/Mobility, etc. He will be able to connect with other animals that don't come from the rainforest later down the line, but that's not explained until after his initial introduction. He's either or a mutant or Inhuman. Unsure of what direction I want to go in.
-Master Hunter/Tracker
-Expert Herbalist (accelerated healing properties, super stamina, psychic meditation, etc.)
-Expert Marksmen with hand held, thrown weapons.
1st Arc idea: Tony Stark would be his first true human interaction, and will start out as his enemy. Stark Industries tears up the rainforest Tame lives in for a project Tony volunteers to do. This is how Tame is initially discovered/brought to light. The 2 go at it a few more times, with Tame not backing down to save his land. (This will be fleshed out more when I put it in story format)
Tame and Tony eventually put aside their differences and defeat the main villain. The guy who is behind the deforestation of the rainforest. Still haven't decided who it will be yet, and what his motivations/ secret project will be. I need someone that will conflict Tame and Tony's morals enough to make them work together.
This eventually helps the 2 see eye to eye, with Tame agreeing to come out of his homeland to become a member of society (and possibly an Avenger), and Tony agreeing to keep a base in the rainforest where it was destroyed for the sole purpose of trying to save it.
Character fluff: He becomes best friends with T'Challa, the Black Panther. T'Challa will be the one who teaches him how to speak, conduct himself, what is right and wrong, and how to harness his powers. So he's crucial to Tame's story.
Favorite fun fact: T'Challa first teaches him African dialect, and then English. So when Tame speaks English, he has a faint African accent. So he's Caucasian from South America that has an African accent lol.
I was thinking after the Tony Stark arc, he could have an arc with Ulysses Klaw as his enemy. A run in with Kraven the Hunter down the line. Maybe an arc with him and Namor? Up in the air for now.
Still thinking of an original Nemesis to create for him.
What do you think? This is the first time I've ever done something like this.