I have recently discovered that I have a superpower: based on a situation, my superpower creates a superpower for me to use. If I'm drowning, maybe it will shapeshift me gills and fins, or allow me to telekinetically attract air bubbles, or just remove the need for breathing altogether.
It tends to start with a certain theme: say, light, time, physical objects, emotions, sound, electricity, chemical reactions, metal - you get the idea. Then it modifies this raw control over the theme it's interested in at the moment and shapes it into a power relevant to my situation. To get from chemistry to flight, maybe it comes up with the power to create combustion at will, which I can use to rocket propel myself.
The problem here is kind of obvious: why am I not a god, then. I always have the perfect power for any given situation, right?
My past attempts as a writer to weaken this power have usually resulted in the character having immense potential but never using it because of lame plot reasons, or the character having a superpower that does all the work for him but he somehow messes it up every time, neither of which are any fun.
The character lives in a world of superheroes, where about 2% of people have powers ranging from super weak to extremely powerful, but I want this character to fall into the 60th to 80th percentile of power strength so that there's still room for non-strength-based problem resolution. In general, I'm trying to use power limitations that are less made-up sounding (so not: he can only use his power on a full moon or something). The pattern that seems to have arisen is that powers themselves have few limits, but the connection between human and power is what causes the limits. Since all powers in universe use the same mechanism, sticking in limits this way should affect all powers, not just one, which makes limiting this one a bit harder.
What are some possible ways this power could be made more fair? I'd prefer solutions that modify the world the character lives in (or 'powers' in general within the universe) rather than the core mechanism of the power, but I understand that small caveats are inevitable.