Yes actually, I think it'd be great if you used fictional characters of your own design. But if you did, then you'd have to post their stats first (any fields of study their proficient in, their strengths, their abilities and their ability limits); for example:
Tyr Krakskul (the guy in my signature)
Race: Warmonger
Height: 10'6
Weight: 986 lbs.
Age: about 30
Hair: White
Eyes: Orange
Abilities: Superhuman Strength, Superhuman Durability, Superhuman Stamina, Superhuman Senses, Superhuman Reflexes, Rollout
Perhaps their weaknesses (like Superman's kryptonite) shouldn't be listed, cuz duh people would automatically try to use that against the person, but at least the stats and maybe any psychological quirks they have...Oh, and a picture should be included, so we can imagine the battle scene effectively.
“…Judge not what a man has done, but judge what he could have done if he was a different bloke altogether. For art thou a leper? And a leper can changeth his spots…” --Rudy Wade, Misfits (Series 4, Episode 8)