[Standard] Atarkas Rage - a swift killer - please help to tune it!

[Klataro]

Atarkas Rage

Simple strategy: Play lots of Mana Dorks, build a ramp to get any Atarka in play and kill your opponent quickly.
Supported by Generator Servant, Dragon Tempest and Xenagos, God of Revels this may be extremely explosive in an early stage.
Example:
T1: Forest + Elvish Mystic
T2: Mountain + Shaman of Forgotten Ways
T3: Land + Generator Servant or Sylvan Carytid
T4: already at least 7 Mana to cast Atarka World Render - remember, it gets haste from the Servant!
With Xenagos, God of Revels in play this would be a serious threat: a potential instant kill

Not to mention Savage Ventmaw which offers you 6 Mana and with haste it will be devastating. Depending on the opponents deck, take in Craters Claws and punch your opponent with your rich mana, or use feed the clan against plenty of direct damage.
Of course, any mass removal is always a threat but i hope in most cases the enemy will not be even quick enough to react. A Crux of Fate is not that effective: either it kills all your fatties or your mana dorks - i both cases there is plenty left: either attacking force or just lots of mana to cast the next dragon immediatly.

The Sideboard:
not quite clear yet. I am not so much aware of the metagame after Dragons of Tarkir. Perhaps some Naturalize or other defensive spells to get rid of nasty entchantments like Banishing light or similar spells. Please suggest!!!

The deck lacks blockers and defensive tricks, but the goal is to beat your opponent down as quickly as possible before he does. With Atarkas ability to deal damage and with Frontier siege and Craters Claws you are still able to clear the path.

I am not shure about Frontier Siege. It provides 2 more mana or helps to keep the enemys army under control but i am not shure if i really need this extra mana or if i have to be very aware of the enemys Creatures as long they dont are flying deathtouchers ... this would be bad but at least i have flyers with trample.

So what do you think about my sketch?
Any comments / suggestions / critics welcome!

Greetings Klataro