Supernormal powers may or may not be available in a given game. They are not appropriate to all genres.
The best way to design a supernormal character is through close discussion with the GM. A player should describe what he wants the character to be able to do, and the GM will decide if that’s within the limits she has in mind for the game. If not, she’ll make suggestions about how to change the character to fit her campaign.
Supernormal powers are treated as powerful gifts, with availability set by the GM. The GM may decide that each player can take two Powers for free, for example, or five, or more. The player may make a case for further Powers, but may need to take faults to balance them.
Some Powers are so effective that they are worth more than other Powers. In the Objective Character Creation system, the GM may set the cost of a certain supernormal power equal to two or three “average” supernormal powers. In some cases, the GM may veto player suggestions outright: omniscience and omnipotence are good examples!
The GM may decide that supernormal powers may be pooled with other traits for trading purposes. In this case, one average Power is worth two gifts. For example, a player who wishes to play a magician in a fantasy setting will need to trade some skill, attribute, or gift levels to buy magical Powers.
Undefined Powers have a default of non-existent that is, they do not have a default value of Fair, like attributes, or Poor, like skills. If a supernormal power is not defined for a character, he doesn’t have it.