Orthworm might be an energy-hungry card, but with three Metal Energies, it gains 100 HP, pushing its max HP to 230, nearly as high as an ex
Knowing when to quest, when to challenge, when you use your actions, etc
And the Eldrazi are all colorless and great ways to dump 10+ mana in a single turn
And there are Contract from Below and Library of Congress as cards that chew through these 9 cards
It won't turn any land into a basic land or remove the legendary supertype from a legendary land, and the lands won't be named "Mountain."
Abzan Greasefang is the perfect example of a deck where this card shines as the deck relies on its namesake creature, Greasefang, Okiba Boss, staying on the battlefield