Fiddlesticks Runes ?

I go First Strike-Hexflash-Triple Tonic-Cosmic Insight and Grisly Momentos-Ultimate Hunter but the new rune the Axiom Arcanist just looks too good but i dont want to give up on Grisly Momentos. If i go Domination primary i'll lose the true damage that First Strike provides and i can't decide. And i thought maybe my fellow Fiddlesticks mains will help me decide ?