The explosion perk does sound nice and the exotic would be fun to use but I feel like you should play with the godfather thing a bit more. How about instead of a hand cannon, it's a primary pistol. Maybe give it full auto and make it have an old school design. The exotic perk could be that all shots fired overpenatrate and stacking precision hits feed ammo back into the clip. It could also have glass half full to make the second half of the clip absolutely terrifying.