secret lair mtg commander deck Dragons - The Ur-Dragon - or both Building An All Secret Lair

Shield counters act like temporary totems - surviving board wipes, combat, and pesky removal spells

Equipment has to be cheap to play and cheap to equip in decks that splash them, and Conjurers Mantle is both

Shadowspear helps ensure you have consistent access to lifegain and trample for your ring bearer, with the side benefit of letting you remove hexproof and indestructible from opposing threats, and can be searched up with Urzas Saga

I wouldn't be surprised if it turns up in older formats as well

The singularity foil effect was crafted specifically for this set, and it's something that needs to be seen to be believed