If you could control any element or celestial power what would it be?

How would you control and manipulate your surroundings. For better or for worse.If you could control any element or celestial power what would it be?
I would like the ability to control the weather every now and then. Like in the summer when it is over 30 days with triple digit heat, I would like to just wave a magic wand and make a sudden gentle rain, and maybe a nice cool front, just to get a break from the overbearing heat.If you could control any element or celestial power what would it be?
That element would be hydrogen. Why Hydrogen? B/c ALL other elements are made out of it. By amassing lots of it you could create large graviational fields. By controlling small amount of it you could regulate chemistry and forces such as hydrogen bonds or vanderwals. Hydrogen is cool!