Searching up cards like Daybreak Coronet, Spirit Mantle, and Ethereal Armor will make Zur more and more powerful, and he will quickly become a virtually untouchable enchanted monster capable of one-shotting other players with commander damage
The cheap cost twinned with the flexibility and smash-ability is strong enough to make a mark with a lot of decks
A dredge 5-6 effect is often enough to put this card in the graveyard and cast it via delve
6 mana is a lot for a glorified Steelshaper's Gift, but the mana cost is more bearable if you wanted to fetch Hammer of Nazahn with him, and he does tap down potential blockers as well
As easily the sets best card for the 99 of Commander decks, The Soul Stone is a true staple
You see, whenever you cast a spell of any type, you can choose it put it on the bottom of your deck