Its a classic, and for good reason
My advice is to just play with things
Creature - Elf Shaman Color tag templates(None) Shrieking Drake Flying When this creature enters, return a creature you control to its owner's hand
So, thus far we know that Felothar, khan of the Abzan, or Abzans Mythic Spirit Dragon, Betor, lead the Abzan Armor EDH precon Ureni, spirit dragon of wisdom, or Eshki, leader of the Temur clan, can lead your Temur Roar Commander precon you can command your Sultai Arisen precon with the Mythic Spirit Dragon, Teval, or Kotis, leader of the Sultai clan and either the Mythic Spirit Dragon, Neriv, or Zurgo, leader of the new Mardu can be in the command zone of your Mardu Surge Commander precon
Whether a booster box contains draft boosters, set boosters, or collector boosters, the Box topper of said box will always be a random Dracula promo card in foil