Risk Factor is a risky card! Well, not for you but for your opponent. It's similar in effect to Vexing Devil, a frequent choice for some of the most aggressive decks in Modern. So you may already see where it's going.
The Risk Factor's Jump-Start ability synergizes the best with Madness decks that use cards like Firey Temper and Alms of the Vein. Here you can discard cards and pay less mana for your burn spells. This kind of deck can also work well alongside such cards like Hollow One and Vengevine.
Just like Mission Briefing in Jeskai variant of the deck, Risk Factor will work great in the Mardu List. That damage won't even matter as soon as you can draw six cards off one copy of Risk Factor.