I actually found a better line! It's close to your solution, but more optimal.
Turn 1:
1. Play Arid Mesa, crack it and fetch Badlands
2. Cast Imperial Seal tutoring Underworld Breach to the top of your library
Turn 2:
3. Play City of Brass and tap it for {R} to cast Rite of Flame for {R}{R}
4. Cast Underworld Breach
5. Tap Badlands for {B} and exile Elvish Spirit Guide for {G} to cast Demonic Tutor searching for Lion's Eye Diamond
6. Cast Lion's Eye Diamond, and crack it for{B}{B}{B}, and discard hand.
8. Re-Cast Demonic Tutor from graveyard, leaving {B}, and tutor Rain of Filth.
9. Cast Rain of Filth, and sacrifice both lands, making {B}{B}.
7. Re-Cast Lion's Eye Diamond from graveyard, cracking it for {U}{U}{U}.
10. Re-Cast Demonic Tutor from graveyard, tutoring Brain Freeze (you will only have Demonic Tutor left in graveyard)
11. Cast Brain Freeze for Storm=8 and get lucky.
12. GG!
