Fortunately, there are many cards in MTGs history that trigger at the beginning of your upkeep to benefit from Obekas ability
In a deeply interactive format playing only sorcery speed is annoying, and it also stops a ton of cards such as Cascade spells, Shelldock Island, Instant Madness cards and Bring to Light
But you can also create a combo style deck that relies on untappers to build up infinite mana, or uses them with Lathril herself to close out the game
Dack Fayden Arguably the best discard outlet here but let down by being gold and thus somewhat harder to play

Advanced Search Sets Random Syntax Release date: 2016-11-15 Armored Griffin Chaotic ther Auramancer Interplanar Tunnel Auratouched Mage Morphic Tide Cage of Hands Mutual Epiphany Celestial Ancient Planewide Disaster Felidar Umbra Reality Shaping Ghostly Prison Spatial Merging Hyena Umbra Time Distortion Academy at Tolaria West Kor Spiritdancer Mammoth Umbra The ther Flues Agyrem Sigil of the Empty Throne Akoum Spirit Mantle Aretopolis Three Dreams Astral Arena Augury Owl Bant Cancel Bloodhill Bastion Concentrate Celestine Reef Guard Gomazoa Cliffside Market Higure, the Still Wind Illusory Angel The Dark Barony Edge of Malacol Mistblade Shinobi Eloren Wilds Ninja of the Deep Hours Peregrine Drake The Eon Fog Feeding Grounds Primal Plasma Fields of Summer Sakashima's Student See Beyond The Fourth Sphere Furnace Layer Sunken Hope Gavony Walker of Secret Ways Glen Elendra Wall of Frost Glimmervoid Basin Whirlpool Warrior Assassinate Goldmeadow Cadaver Imp Grand Ossuary Dark Hatchling The Great Forest Grixis Ink-Eyes, Servant of Oni Grove of the Dreampods Liliana's Specter Hedron Fields of Agadeem Okiba-Gang Shinobi Skullsnatcher The Hippodrome

Other than that, it was more or less the same dominance as in Standard: Boros energy and its three color variants immediately shot to the top rank for both usage and winrate, the various build-around energy cards all proved to be at least viable, and even control decks adopted the new energy-based interaction