Hmm.. i think that deck needs some tuning.
First of all, why 42 lands? I would suggest to go down to 36-38 and add some more ramp in stead. Felwar Stone,
Thaumatic Compass (yes, hes damn slow, but also gives utility later on),
Armillary Sphere,
Expedition Map (also gets non-basics),
Burnished Hart,
Solemn Simulacrum,
Myriad Landscape. Then you cold replace
Rupture Spire with Path of Anchestry (same slot but waaay better).
Neheb, the Eternal could also be an interesting option for your deck.
Then you already got
Havoc Festival, what about
Archfiend of Despair as win condition?
Besides that, Morganator already mentioned that you need more pingable damage. an interesting combo for this could be
Goblin Sharpshooter + Deathtouch (
Gorgon's Head,
Basilisk Collar for example). Kill all creatures you dont control and ping 1 damage to an opponent afterwards to cast your commander.
Besides that,
Abyssal Persecutor is a baaad idea without an sac outlet, he could break your neck. I also dont like
Diabolic Revelation unless your focused on combos, play
Beseech the Queen in stead. Since you're playing tribal, you could replace
In Garruk's Wake with
Kindred Dominance.
Then I would suggest adding
Phyrexian Reclamation (recursion) and
Filth (kinda nasty combo with
Urborg, Tomb of Yawgmoth). You should also drop
Trespasser's Curse because it doesnt fit into yur strategey, unless you add some cards to
flash Rakdos.
/edit: a last suggestion: unless your usually playing 1vs1 i would suggest replacing
Murder with
Curtains' Call.