When it comes to your characters, you should have a basic build system. For those that role-play, you know what I'm referring to; it's how you create characters. For those that don't do much role-playing, this should be an interesting entry...
“Character build” refers to how you create characters; specifically, it's a standardized process that allows you to quickly create characters, even if you need to create one on the fly. What you need to do is to create a system that allows you to create realistic characters smoothly and quickly. Although I could cheat and recommend the Champions system (which is complete (arguably too compete)), instead I'll lead you through my process.
The first step is to determine what role the character will be playing in the story. You can be as simplistic as hero, villain, sidekick, or bystander, for example, or work the character into the theme (“the character shows the hero that there is always hope”, for example). The more specific you can get the better, as the more specific you are at this stage, the simpler the other stages will be. It's important that you know what role the character will play; even if it amounts to a cameo, the character needs to do something or you're just wasting words, and every one of your words should be well-chosen.
Once you have established what the character's role is, you can then assign a power level. Even in stories where magic and superpowers aren't used, characters tend to have power levels defined in terms of the story; in a military story, for example, rank, experience, and access to weapons and vehicles would define power. In a high school setting, social status, skill sets, and grade level would be determined by power level (a senior with impressive hacking or athletic skills who is capable of asking anyone for favors would have a high power level, for example).
You should limit the number of god-like characters, however. If you have a lot of them running around, it quickly becomes a question of either why they don't take care of the problem, or why characters would want to know everything when they can't use that power. Tolkien had the right idea; the important action was in the background with Frodo, and the power characters were put on the front lines. Even Tom Bombadil was used to effect, even with his limitations of where he could go.
Even if the setting is exploring extreme powers, you need to keep in mind that the characters should not be the most powerful beings in the story. Even Superman and The Authority are not the most powerful beings in their respective comics; there are still entities that are more powerful than them. It's not a balance issue; it's more that, if they were the most powerful entities, there would be no challenges for them, and they wouldn't be as interesting. They would walk through any challenge and you would hard-pressed to come up with an interesting adversary for them, and without an interesting adversary your story would be boring before you even got out of the gate.
You should then determine the character's personality; combined with the power level and role, the personality will determine appearance, abilities, and other basic characteristics. You should define three personality traits, two good and one bad. That should give your character a balanced, three-dimensional personality. While you're at it, go ahead and give the character two to four advantages, things that he does that he does better than other characters, and that allows him to stand out. Also, define one or two negative qualities. Being an apprentice bears special noting, especially given the number of sidekicks and young heroes; an apprentice should be considered a negative attribute, but only because the character is sharing some of his uniqueness with someone else.
And that's my quicky character generation process. All other features should be easy to define; the broad strokes have been painted in, and you should just need worry about details. Hope this helps!