Originally Posted by Carados
Honestly, you're better without it, just like in most games on Summoner's Rift.
I don't play blitz much in Dominion, but your are mistaken about SR. IF you intend on actually being an asset to your team with tanky items, you absolutely need manamune and an early sheen to be able to do anything at all.
Manamune is pretty much the perfect item for blitz in that it amplifies his E as well as providing the mana bonuses; there is no reason not to get such a cheap item considering you should be rushing tear.