With great caution! ;)
I jest. However, there is a note of truth to that. Don’t forget the famous Uncle Ben quote: “With great power comes great responsibility”. It’s your responsibility to not let your character’s power become too overwhelmingly out of control, or let his temper become his whole personality. Making a character whose whole existence is based purely around his bad temper and powerful power without taking special care to flesh him out otherwise will quickly turn him into a caricature, like what somebody who has never watched Dragon Ball Z and knows nothing about the personalities of the individual characters might think about the Sayans. (They would seem a bit silly to the uninformed, wouldn’t they?)
A character with a quick temper has a great opportunity to grow as an individual, provided you take into consideration that his temper is his weakness, not something that bolsters his strength or something positive about his character. People have to walk on eggshells around someone with the propensity to blow their lid at any given moment, and eventually, if he keeps it up, nobody would realistically want to spend time around him at all. What is he doing to try to keep his temper under control? Is he making that effort, or is he simply barrelling through life with the “if you don’t like it, get out of my way” mentality that a lot of underdeveloped characters, unfortunately, tend to carry around with them?
Another thing to consider is, does his power directly connect to his temper? I, myself, have a character with a fiery temper and a strong power, and the two are directly connected, which means that when he loses his temper, it has disastrous results, which gives him more motivation to keep his temper in check. What is your character’s motivation to keep his temper in check? What exactly sets off his temper in the first place, and is there any possibility that he might be able to develop as a character to try to work through whatever it is that gets him worked up? Does he have a tendency to abuse his power when he is angry, and does he feel guilty about using his power when angry, afterward?
This does not mean, at all, that your character should never lose his temper, or abuse his power, whether the two instances are connected or not! People make mistakes, and human (or, mutant, as the case may be) error is a part of growing up and developing as a character. Just make sure that if he does lose his temper, there are comparable consequences. Too many times I’ve seen a character lose their temper or abuse their power and not even receive a slap on the wrist for it because “she can’t help it, she’s too powerful/so angry/a klutz/it’s who she is”. If I or you or anyone else were to blow up a city block, we would definitely not get off with an “oh you silly mutant” and a good-natured shake of the head.
Even if your character is a villain, you don’t want to turn him into a gravel-chomping parody of a more fully-developed version of himself (unless you do, but judging from your question, I take it that you don’t). Where does his anger stem from? Is somebody else abusing his tendency to blow his lid for their own gain? Is the fact that he has a short temper just a halfway crutch that makes it easier for him/you to abuse his powerful power? Try taking away his powerful power for a bit, and see how he reacts – and how it makes him feel about his temper after he realizes just how ineffective he is when all he can do is throw a tantrum without the ability to punch through a wall, or… whatever his power is.
Experiment! Mess with him! Throw him some curveballs and see how he comes out in the end. You might just be surprised by his development (or he may stubbornly resist development – some headstrong characters do – in which case you simply have to switch tactics on him). You control him, not the other way around!
And don’t forget the most important part of roleplaying – just have fun. :)