The Soul Stone is found in Spider-Man and provides black mana
It's worth noting that commander tax will make this a fairly mana-intensive gambit so this plan is unlikely to be playable in faster metas where your decks have to be leaner, faster and more efficient than the decks you see in casual play
The sliver creature type was later introduced in the Tempest block
While some of the artwork is reused from existing cards, the majority of the cards feature original designs, ensuring the mobile game feels fresh
Choose a Background Illustrated by: Andreas Zafiratos Volo, Itinerant Scholar Commander decks Not Legal Traditional Standard Not Legal Traditional Alchemy Not Legal Traditional Explorer Not Legal Traditional Historic Not Legal Traditional Timeless Rulings 2022-06-10 Choose a Background is a variant of the partner ability
Since her copy effect has no limitation on uses per turn, and no cost other than tapping, all you need is an instant or sorcery which can untap Stella while producing any other cumulative benefit