Personal Arcs don't have to be based in a characters past, meaning that if your personal arc is just a situation the gang finds themselves stuck in and your character saves them and gets some strong character development, then it's fine.

The only real problem I have with this character is his power. I think the power itself is a great concept, using gambling (what I always think of immediately when greed is mentioned) as a way to manifest objects to fight with. However, the problem is how to determine fair number roles. I mean, the only thing I can really think of is before each fight, you message me via pm, tell me how many times you roll, then I use a dice generator system to determine the rolls. It's not that I'd be opposed to this, but it just seems a little inefficient, unless you have a better idea?