Legendary creatures such as Mogis, God of Slaughter or Kaervek the Merciless, which actually appear in the Endless Punishment deck, have been the backbone of previous iterations of red-black group slug decks, and senior game designer Daniel Holt leaned on that archetype history to help shape Endless Punishment
However, blue creatures often see play in the current Standard in their own mono-colored decks
Group bulk cards by set, type, or rarity tier
Its a great combo with something that sacrifices an artifact (Krark-Clan Ironworks, perhaps?) and artifacts like Spine of Ish Sah and Portal to Phyrexia that impact the board
If a card is worth casting, its worth casting more than once and Mizzixs Mastery offers you the option to either cast your best instant or sorcery twice per game, or recast your entire graveyards worth for 8 mana
If you have not yet read my previous article on Throne of Eldraine Season Rewards and Real World Value, then check out that article HERE While that article goes very in depth on how values are calculated, fortunately you won't need to do any math at all to figure your collection value out