Yesterday I said in passing that I'd drafted a Gruul deck, just because it seemed like the thing to say rather than "red-green." Ravnica did everything it set out to do and more, but it showcased a problem that had been there in Invasion as well
Monsters (36) Armageddon Knight x2 Blackwing - Zephyros the Elite Broww, Huntsman of Dark World x3 Cannon Soldier Danger

Deck 2: Yami Marik Style The Winged Dragon of Ra Deck 2 The Winged Dragon of Ra 1 The Winged Dragon of Ra Sphere Mode 1 The Winged Dragon of Ra Immortal Phoenix 3 Juragedo 3 Guardian Slime 2 Reactor Slime 1 Lava Golem 2 King of the Swamp 1 Monster Reborn 3 Ancient Chant 2 Millennium Revelation 1 Blaze Cannon 1 Foolish Burial 1 Polymerization 2 Salvage 2 Pot of Extravagance 2 Trap Trick 2 Booby Trap E 2 Metal Reflect Slime 2 Mirror Force 1 Nightmare Wheel 2 Crackdown 3 Egyptian God Slime 2 Thousand-Eyes Restrict 1 Millenium-Eyes Restrict 2 Linkuriboh 3 Salamangreat Almiraj 2 Secure Gardna 2 Black Luster Soldier Soldier of Chaos Deck Concept Tribute Metal Reflect to Special Summon Egyptian God Slime from the Extra Deck, which can, in turn, be Set to the Spell & Trap Zone from the hand, Deck or GY by the second effect of Reactor Slime, while Booby Trap E allows it to be Reset on the field from the GY

Beyond how easy it is to summon, the card can also destroy an opponents monster once per turn, but it becomes unable to attack until the next turn
Invasion of Fiora Invasion of Fiora Battle Siege (As a Siege enters, choose an opponent to protect it
They can respond to this by tapping all of their lands, but it means that they only get one phase to cast things in