Players should pick Dungeon Delver if building in the UB archetype, a Background Enchantment that gives your commander the ability to trigger room abilities in the dungeon for an additional time
It also triggers for everyone
But theres something that feels very cool about dropping a land thats legendary with a cool name
Seven mana sounds like a lot to transform a card, but if you don't win the game after transforming this then things have gone horribly awry
Mixing a variety of counters, proliferation, graveyard play, and everything all together is for a really strong deck, with a bunch of new cards, and valuable reprints
Ensuring you can soon hit all five colours among other permanents, with cards like Jodah, the Unifier, turns her into a monstrous 7/7 too, thats Lord of the Pit stats