My character would be a mix of three of games.
1. Assassin's Creed
2. Splinter Cell
3. Watch Dogs
First of all, I like sneaky and hacking type of games. I would like to have the agility to climb buildings and structures with ease like in Assassin's Creed, sneak through air vents and tight spaces like in Splinter Cell, and of course hacking phones, computers, networks and stuff like in Watch Dogs. For me an open-world is not really "open-world" if you cannot go almost anywhere in the game. Now for me that would be an ultimate character.