Your Mana Curve is all wonky. I agree with AlchemicalPanda in that once you get Sheoldred and the Wurm out you will be fine, but till then....
Permalink
Well you can't pick Colorless for the Caged Sun, and it is too expensive for ramping your mana. Arcbound Crusher still fits- it is only 4 mana.
Consider adding Arcbound Reclaimer to bring back the guys you sacrifice to the Ravager. Adding an Arcbound Crusher would make cycling through your cards like that even more powerful. Since you mention that it is a major card for you, wouldn't you like to add at least one more Pentavus? You can use Metalworker for a HUGE mana boost for it all to get working. You could also add Energy Chamber for more free tokens- always a good thing! It is all up to you, these are just a few cards in my own Arcbound deck. :)