It has been updated by The Relentless Dragon, in 2021
I owned a lot of the cards shown here and some of them I still own
Completely revitalized my collection, making finding cards and building decks so much easier than the system I had tried to create myself
It's the majority of the set, and it provides the structure and stability
5-Color Niv-Mizzet by Michael Rapp 2 Paradise Druid 4 Sylvan Caryatid 1 Dreadbore 2 Abrupt Decay 4 Teferi, Time Raveler 1 Unmoored Ego 1 Deafening Clarion 3 Uro, Titan of Natures Wrath 1 Supreme Verdict 1 Utter End 1 Nahiri, the Harbinger 3 Siege Rhino 1 The Scarab God 1 Tolsimir, Friend to Wolves 4 Bring to Light 3 Niv-Mizzet Reborn 1 Cut // Ribbons 2 Botanical Sanctum 4 Fabled Passage 1 Forest 1 Godless Shrine 1 Island 2 Mana Confluence 1 Mountain 2 Opulent Palace 1 Overgrown Tomb 1 Plains 2 Sandsteppe Citadel 2 Spirebluff Canal 2 Stomping Ground 1 Swamp 2 Temple Garden 1 Watery Grave That makes my choice of flex slots: 1 Dreadbore 1 Unmoored Ego 1 Deafening Clarion 1 Uro, Titan of Natures Wrath 1 Nahiri, the Harbinger 1 Siege Rhino 1 The Scarab God 1 Tolsimir, Friend to Wolves 1 Cut // Ribbons As you can see, I went into the weekend ready for aggressively-slanted creature decks, like Mono-Red and Mono-Black

With this list, while your opponents may be digging for combo pieces or trying to pick apart your board, you can use Soulflayer and Urborg Scavengers to ignore all that and beat them down