RP Character Backstory question (OOC)

I've just started rolling a Tanker I'd like to start RPing with, and I've come up with a backstory.

Basically, he's inspired by Hawkman from D.C. Universe (Natural Inv/WM Tanker with wings and some armour)

He's from another planet, a scout for his people's military to assess weather or not Earth poses a threat to his kind. To cut a long story short, he decides Earth poses no threat and could actually make a valuable ally. Inspired by the likes of Statesman and Positron, he decides to stay on Earth and help by fighting crime (somthing which does not exist on his homeworld). I also want to explain his powers, most importantly, why he can't fly untill Level 14. I've come up with a fairly decent solution but I want to ask the more experienced RPers if this is doable?

Okay. He arrives on Earth and finds out he can't fly, after scanning the atmosphere using his ship's sensors. He detects a lack of a gas that is present in his own world's atmosphere, and without it he cannot fly straight away. However after fourteen weeks of training and practice his body adapts to the lack of atmosphere and he can then fly as effortless as he could back on his homeworld.

I was going to documentate it like this:

1st Week: an run slightly faster than humans, and his wings can propell him into a high jump (Sprint)

4th Week: Can run much more faster and jump much higher than he could when he arrived, has gained a lot of his agility back (Ninja Run)

12th Week: Can now fly but extremly slowley compared to flying back on his own homeworld, but can hover mid air indefinatley (Hover)

14th Week: After much physcal training and practice, he can now fly in Earth's atmosphere as effortlessly as he can in his own atmosphere.

Does this sound feesable, or does it step on any of the game's Lore?

that sounds perfect and It also has nothing to do with the game's lore.

1. Feasible has nothing to do with explaining powers in any way. There is no real gas which could possibly exist to allow someone to fly. This should not stop you from using this as the explanation.

2. Your explanation does, however, kind of fit the 'Earth has heavier gravity than my homeworld' school of flying heroes slightly better. (Not that that makes any more sense in physics, but worth considering.)

3. My only real comment is that if it takes you 14 week to get to level 14 that really will be denying the laws of physics!

If I might add my two cents, both some special gas allowing him to fly and lighter gravity allowing flight are both fairly improbable according to physics as I know them. Saying the earth has a less dense atmosphere would be far more reasonable - by what I remember of high school physics, staying aloft in a denser atmosphere is easier than in a thinner one. Or I could be completely misremembering things.

Or your character may not even use the same principles of flight as birds and aircraft here do - if he relies on some biochemical process with the aforementioned gas to provide lift rather than the standard 'air flowing faster over one side of wing creates lift' then the gas would indeed be reasonable. Though that would invalidate the being able to train himself to fly in Earth's atmosphere so maybe not.

In short, you can explain anything in the CoH universe if you put enough pseudoscientific words together. It's a comic book universe, people don't expect things to be operating under the same laws of physics we have here in the boring old real world. Having that mostly reasonable explanation worked out can come in handy though - more than once someone's asked my characters how or why their powers work.

Thanks for the responses guys, and I think the 'gas' needs an explination.

The gas itself (have yet to come up with a name) is like a supercharged version of Helium, which as you know is lighter than air. The wings on these people help to lift them from the ground and propell the through the air, and a lungfull of this gas can almost half the bodyweight, so not much effort is required to fly on their homeworld, (Most of the life forms on this world is winged and can fly. Avian creatures are worshipped) and the constant breathing keeps them from flying out of the atmosphere and dying.
On Earth however, this gas isn't present in the atmosphere, just oxygen and all the other crap we've poured into it, unfortunatley, none of them is lighter than air so when he arrived on Earth, he found that he couldn't fly at all, all he could do is push himself upwards a few feet higher than an average human can jump (please note, the average height of these people is around 7'9, my character is just over 8 foot tall, and they're extremely strong)
However, after 14 weeks (1 Level per week, not me leveling up, but just so people understand that he couldn't fly even though he had wings. I could change this to days) of hard training and determination (His people are warriors, therefore extremely discaplined when it comes to training, plus their bodies are adaptable) he learns to make do without the gas and strengthens the muscles in his wings.

I hope this explains

What about some kind of internal lighter then air filled sac, a little similar to a swim bladder in a fish sort of, would that be any help Birdy?

It seems to me that you're attempting to explain why your hero loses the ability to fly for a time after coming to the Earth of the CoH Universe.

Pseudoscience, here we come...

His species are naturally adaptive, and possess human-level curiosity, which has driven them to the exploration of many other worlds, and seeing multiple alternative cultures. Physically, they fit approximately within the range of human norm, with the exception of large wings. Their bodies are constructed of a complex bio-adaptive substance which does the job bone and muscle would in humans. This adaptivity allows their body density to be altered as well as their effective "muscle" strength. It takes a relatively short time for their body to evolve to suit a particular planetary gravitational field and atmospheric density, but over the course of a few weeks they will again regain the ability to fly.

Since this is pseudoscience fudging, there's no need to explain what happens when they go to a world with vastly different gravity and atmosphere to Earth, because all of the worlds thus far visited in CoH are Earthlike. Even the Shadow Shard. But feel free to build on that for an explanation.

tl;dr No "normal" skeleto-muscular system will allow you to do what you want. So make up an abnormal one.