Eldrazi

"On this plane, the use of magic can provoke a ferocious reprisal from nature. Whoever the Eldrazi were, their relics left Zendikar forever enraged"- Jace Beleren

The Eldrazi are a long dead ancient race native to Zendikar. They had a huge boner for even huger statues and wacky architecture. Just kidding, they are mindless lovecraftian abominations with an appetite that makes Tyranids look anorexic. When Tyranids are through with a world there is at least a barren piece of rock. They also make tyranids seem like natives to wherever they are attacking. These cosmic horrors are so alien they don't even truly enter the plane they feed on. They have their (physical) shadows go in. Then the shadows go super organism, creating lesser Eldrazi and swarms of brood that devour the plane of mana and life energy while the actual Eldrazi Titans (e.i. the actual Eldrazi) just chill in their home, the Blind Eternities. These are represented as creatures, and drones aside, colorless creatures. The only other colorless creatures are artifacts and morphed permanents.