Bloom Tender or Birds of Paradise are classical choices (with the birds you can call your commander in your second turn!!!), and we got a nice usage of Rattleclaw Mystic: Morph him in your second turn and face him up in the third to call Animar
Along with that, Ashiok also has a passive ability that reads: If you would pay life while your library has at least that many cards in it, exile that many cards from the top of your library instead. Basically, theres a very strong theme here
With that in mind, Nyx Lotus is currently going to cost shoppers about $10
Bloodbraid Elf, Qasali Pridemage, Rakdos Charm (which has been performing incredibly well so far), Izzet Charm, Sphinx of the Steel Wind, Olivia Voldaren, Lotleth Troll, Edric Spymaster of Trest, Lightning Helix, Shardless Agent or Geist of Saint Traft all of which are so similar in their power
Mondronen Shaman is an example of this, and it could be expanded into werewolf versions of Harsh Mentor and Ash Zealot
If the condition of the card is superior to that of the majority, grading it will increase its value (to a greater or lesser extent) on the secondary market