Swords to Plowshares is a staple in EDH period
This card adds another useful piece to the puzzle, functioning as yet another Amulet effect, or more accurately, a Spelunking variant, that you can tutor for with Summoners Pact or Green Suns Zenith
While Promise of Aclazotz can create a demon on its own thanks to Foul Rebirth, there's no need if that demon is already floating around
It works pretty well in multiples, too, since the demon from one room qualifies for the Annex of another
For each deck, I like to find a three-mana-value rock that has a cool side ability
Some players wait to cast Talrand with a mana to spare to represent a counterspell or a card like Opt to at least make a Drake if your commander dies