You can transform the artifact at any time for two generic mana, turning it into a Token Artifact Creature Phyrexian, a 0/0 that also retains those +1/+1 counters
You can cast it large, or you can cast it small, but no matter what, you wind up with a cost-efficient creature
Voidslime has gotten better over time with more planeswalkers and their frightening ultimates offering great things to Stifle
We're spoiled for choices these days for what seven mana can buy you, between The Endstone, Ugin, Eye of the Storm, and Sire of Seven Deaths, but turning landfall into card advantage with The Endstone gets a huge nod in a format with Icetill Explorer, which can power out The Endstone on turn five
From tweaking cards in the mono-blue version to maybe going crazy and playing Green for Explore and Rites of Flourishing, Turns has a bright future in Modern
White Auracite