5 Realmwalker A Changling Master Similar to Herald's Horn, Realmwalker is a Changling creature, meaning that it has every creature type possible all at once
You will have to play it after combat to get the token, and that will be fine if you build your deck with this in mind
Alacrian Jaguar Autarch Mammoth Congregation Gryff District Mascot Drover Grizzly Giant Beaver Lagorin, Soul of Alacria Ornery Tumblewagg Rambling Possum Seraphic Steed Stubborn Burrowfiend The Gitrog, Ravenous Ride Venomsac Lagac
What makes it so good is that it has a secret second mode: you can exchange control of it with something else, and then just not pay the energy, and what you stole will be sacrificed
A *LITERALLY* UNTAPPED RESOURCE Convoke, conspire crew, harmonize, saddle, and now station: these are the mechanics which allow you to pay costs by tapping random creatures you control
Its purpose is to add narrative context and lore to the card's mechanics or theme