1) And so it came to pass.

2) Well, I see invisibility one of three ways, either it’s imperfect and you can still be seen if somepony looks hard enough, it’s time sensitive in some way so you can’t use it exactly when you want for as long as you want, or it’s constant and you’re invisible forever.

But my standby will always be total density manipulation. That gives you:

a) Flight (or rather control over lift and descent, you’d still need some outside means to propel yourself)

b) Super Strength (because your denser muscles would perceive no change when becoming super dense)

c) And can make you Practically Invulnerable (you could catch a dragon’s swipe with ease, but you’d still catch on fire normally, or at least I’d assume so, let me know if I’m wrong)

Of course, you couldn’t have all three at once. But I suppose the main restriction would be that it would take a few seconds to transition from one extreme to the other. You can’t suddenly become super dense to stop a bullet or catch a wrecking ball, you’d have to already be prepared.

That said, I can use minor density manipulation. It’s how I can amplify my strength and punch a hole in a wall. You need a denser body to throw a real punch without shattering bones or ripping your skin off, that’s why I can’t maintain it very long. It’s not just one power, it’s really a collection of spells. And as much as I’ve practiced using them, I’m not very magically inclined.

Also, when I say total manipulation, I’m talking total control over your whole body. That would also entail enough control over your body’s cells to not drift apart when becoming lighter than air.

Thermal manipulation is a close second, since that would also give you not only resistance to extreme temperatures, but also flight and let you become more solid. But that solidity would also be brittle. If an impacted force is too great or you become too cold, you’d shatter. It would just require much more care than I’d like to risk.