The power level of the Dominus and Twilight cycles, matched with the speed boost games will get from an increased presence of poison counters, means that this set is going to have a huge impact on Commander
If it's turned face up in any other way than paying its negamorph cost, you won't put a -1/-1 counter on it

Here is the all important deck list Counts : 100 main Creatures:28 1 Dragonlords Servant 1 Adaptive Automaton 1 Dragonspeaker Shaman 1 Boneyard Scourge 1 Dromoka, the Eternal 1 Kolaghan, the Storms Fury 1 Scalelord Reckoner 1 Scion of the Ur-Dragon 1 Scourge of Valkas 1 Sunscorch Regent 1 Wasitora, Nekoru Queen 1 Broodmate Dragon 1 Crosis, the Purger 1 Hellkite Charger 1 Hellkite Tyrant 1 Niv-Mizzet, Dracogenius 1 Ryusei, the Falling Star 1 Savage Ventmaw 1 Silumgar, the Drifting Death 1 Steel Hellkite 1 Teneb, the Harvester 1 Atarka, World Render 1 Bladewing the Risen 1 Deathbringer Regent 1 Ojutai, Soul of Winter 1 Nicol Bolas 1 Utvara Hellkite 1 The Ur-Dragon Spells:33 1 Earthquake 1 Nihil Spellbomb 1 Sol Ring 1 Dragon Tempest 1 Farseek 1 Helm of Awakening 1 Rampant Growth 1 Seek the Wilds 1 Steely Resolve 1 Anguished Unmaking 1 Commanders Sphere 1 Cultivate 1 Darksteel Ingot 1 Descendants Path 1 Elemental Bond 1 Growing Rites of Itlimoc 1 Heralds Horn 1 Kodamas Reach 1 Temur Ascendancy 1 Crucible of Fire 1 Frontier Siege 1 Syphon Mind 1 Utter End 1 Whip of Erebos 1 Coat of Arms 1 Crux of Fate 1 Gravitational Shift 1 Kindred Discovery 1 Palace Siege 1 Unburial Rites 1 Vanquishers Banner 1 Obelisk of Urd 1 The Immortal Sun Lands:39 1 Arcane Lighthouse 1 Arcane Sanctum 1 Command Tower 1 Crucible of the Spirit Dragon 1 Crumbling Necropolis 1 Exotic Orchard 3 Forest 1 Frontier Bivouac 1 Haven of the Spirit Dragon 3 Island 1 Jungle Shrine 6 Mountain 1 Mystic Monastery 1 Nomad Outpost 1 Opulent Palace 1 Path of Ancestry 3 Plains 1 Sandsteppe Citadel 1 Savage Lands 1 Seaside Citadel 3 Swamp 1 Vivid Crag 1 Vivid Creek 1 Vivid Grove 1 Vivid Marsh 1 Vivid Meadow

Send 1 other face-up card you control to the GY