As for the card itself, The Soul Stone is a monster of a value engine thats, at worst, always useful
But hey, when you want both, you want both
Here you go
As a broad rule of thumb, somewhere around 8-10 spot removal spells is a reasonable amount to play in your Commander deck
I got to the store and met up with recent Pro Tour Qualifier winner Hunter Slaton, along with Pauper professional Alex Ullman, the cool, calm, and collected Rob Kofsky, Hipsters tech guru Dave McCoy, and Draftasaurus Rex originator Hugh Kramer
Remember your silly walk all the way to your table at the local game store, and go all Timmy on players with Magic's coolest pinger ever