Xanathar, Guild Kingpin, for example, is the beholder at the centre of the Xanathar Thieves Guild and here allows you to steal other peoples cards straight from their libraries
Menace is best with lots of small creatures, which is exactly what all these 2/2s are
Four mana is a massive ask in formats like Legacy, but removal that cannot be responded to, which occasionally blows up multiple things, is worth that cost
Come on, people, lets move: Getting Challenger +2 on all of your characters when Lilo is played is great, but youll want to pull her later on in the turn order to make sure you have enough characters on the board to make it worthwhile
+1/+1 Counter decks are all about efficiently adding counters to things, so you'll rarely have to pay 5 mana to adapt it and instead can snag an easy counter off Forgotten Ancient, Master Biomancer, Kalonian Hydra, or something similar