I dont mean to malign their designs, but I wouldnt be surprised if fairly little playtesting went into the creation of cards that the vast majority of players wont ever know exist, much less get their hands on
In Pioneer, Underworld Breach saw heavy play in Lotus Field Combo as it made the strategy unfair and consistent
Search its owners graveyard, hand, and library for all cards with the same name as that card and exile them
However, if you can boost his strength high enough that he wins skirmishes (generally using possessions, Noble Leaders (7R112) , The Last Alliance of Elves and Men (1R49) , or Merry, Friend to Sam (1R302) ), he can discard those minions for you, similar to the way he's used as ring-bearer
The tournament wasnt large, but it was full of stock decks from what I saw: Mono-Red, Green Black, Green White, a couple Teferi, a Mono-Blue player, etc