Muldrotha, the Gravetide decks more than justify their existence with incredible card advantage
Haste + Trample Trample is a useful ability to give to a haste creature
You've got a 3/2 virtually unblockable creature with universal asymmetrical graveyard hate, a la Leyline of the Void, and you can even cash it in for one of the exiled cards free of charge
But you are not buying real Magic cards, you're buying fun playtest proxies
They can keep you from getting too far behind, give you a chance to reset the battlefield, or even win you the game if timed correctly
So, if your commander is Priest of Ancient Lore and the signature equipment is Embercleave, your decks color identity is Boros