Their main use is in decks that are trying to cheat into play some imposing, game-ending threat, whether thats Blightsteel Colossus, Griselbrand, or Atraxa, Grand Unifier
Its perfect with experience CCG players and complete newbies who have never played a card game before
I think Decay will be hard to beat, but depending on the threats that gets played, this might be worth a slot (as it hits Karn and Urza among other things)
Mabel, Heir to Cragflame Now I couldnt leave out the ultimate girlboss and the first revealed Bloomburrow card, now could I
Bomb is mostly used in the context of Limited, where its meaning overlaps with card thats valuable to draft due to game-changing power level
Boones not a big fan of Caesar and I cant imagine he would want Caesar as his commander