I should emphasize, characters have to be from the real world/earth-like world. They are average individuals that might have specific things that could give them enhancements compared to others (knowing martial arts, being great at soccer, was in swim, etc...). 

This role-play is about character development. You want to think about the abilities rationally and reasonable to being FORCED out of your comfort world. Your every day world. And into a strange one where your character have abilities that your character cannot necessarily control at all or properly for a little bit. 

Think if you woke up one day, instead of your bed, you are in a dungeon and when you get up. You shake your hand and a fireball comes out of it. That would freak you out, right? At first at least and then you might try it again. It doesn't work. You throw up your hand and a fireball comes out of it. The characters have to get used to themselves even if it takes 1-2 posts. They have to get a feel and understanding for their abilities and at first, they might not realize they have *all* the abilities that they have. 

Through role-play story and a dice rolling enemies out of existence. Your character will gain experience, understanding, and more for themselves, others, and all around in the categories of physical, magical, and so on.