1. Sceptile: Scars, Ravnica, -M12
2. The Mana Sword: M12, Alpha, Innistrad, -Scars
3. Lopen: Planar Chaos, Time Spiral, M12, Fallen Empires, Homelands, Alpha
4. Shoenin: M12
5. Blair: M12
6. Regaro: Ravnica
7. Tombolo: Ravnica
8. Angelo: Ravnica
9. SpeedYoshi: M12
10. Megaman: Ravnica, Innistrad
11. Crono: M12
12. The Destoyer
13. tcaz: Ravnica
14. pjbasis
15. edwardsdv: M12 or early set
16. Random_Guy: M12, Innistrad
17? GDiffuser: M12, Innistrad
Looks like it'll be M12. As for Diffuser... If we got a bunch more people I'd be able to fit you in, but I don't think that's likely.
--
"As the size of an explosion increases, the number of social situations it is incapable of solving approaches zero." -Vaarsuvius, Order of the Stick