They often include Stage 1 Pokmon and valuable Trainer or Item cards
set symbols) but I think I can answer your question
Brago, King Eternal Ultimate Masters Guilds of Ravnica Niv Mizzet, Parun, Emmara, Soul of the Accord, Lazav, the Multifarious (decklist in the comments), Tajic, Legions Edge, Etrata, the Silencer, Izoni, Thousand-Eyed Commander 2018 Aminatou, the Fateshifter, Xantcha, Sleeper Agent, Lord Windgrace, Brudiclad, Telchor Engineer Core Set 2019 Sai, Master Thopterist, Goreclaw, Terror of Qal Sisma, Vaevictis Asmadi, the Dire, Chromium, the Mutable Battlebond Dominaria Teshar, Ancestors Apostle, Grand Warlord Radha, Arvad the Cursed, Muldrotha, the Grave Tide, Slimefoot, the Stowaway, Yargle, Glutton of Urborg, Squee, the Immortal, Firesong and Sunspeaker, Jodah, Archmage Eternal, Tiana, Ships Caretaker Masters 25 Rivals of Ixalan Azor, the Lawbringer, Etali, Primal Storm, Nezahal, Primal Tide, Zacama, Primal Calamity, Tetzimoc, Primal Death, Zetalpa, Primal Dawn, Ghalta, Primal Hunger Unstable Grusilda, Monster Masher, Dr

The idea is simple: Throw down Slicer, likely converted as Slicer, High-Speed Antagonist to save some mana, slap on some equipment like Sword of Fire and Ice, Commander's Plate, and O-Naginata, then pass Slicer around the table and watch it shred your opponents life totals like a block of cheddar