Disrupt Decorum goads the entire board and forces your opponents creatures to charge headlong into each other
Either a Showcase card or another special thing from the set
In a deck focused on milling, this ability can provide late-game answers to a host of overwhelming board states from your opponents
3/2 Illustrated by ikeda_cpt Standard Legal Alchemy Legal Pioneer Legal Historic Legal Modern Legal Brawl Legal Legacy Legal Comp
While they do enter the battlefield tapped, they also let you Surveil 1 as they enter the battlefield
Also similar to lands, one of the big reasons that Commander 2018 was so poorly received is that the decks were severely lacking in good colorless cards (in fact, for half of the 2018 decks, the only colorless card worth mentioning was Sol Ring, which has been in every Commander deck since the start of the series)