Despite this particular stipulation making Treasure Guardian, Protector of the Cave useless unless at a location, location cards are well worth putting in your deck - not just because they make this card a lot more viable but also because they grant you passive lore every turn, meaning you dont need to actively quest with them to get it, and cannot be targeted by direct damage unless the card being used indicates it can
It also requires Necrovalley on the board again, any good Gravekeeper's Deck should have it on the board anyway
Then at the next end phase, you would set another spell card, The Third Sarcophagus
Duelists can play these new cards on their own, but if they use them with the original Valkyrion the Magna Warrior, also included in this Structure Deck, they can Summon the new Imperion Magnum the Superconductive Battlebot
Heres the magic trick with Mishr, we use cards that counter our own artifacts, like Blood Funnel
By itself, this card wasn't strong when it was released because it needs a lot of energies