In the meantime, you can watch the debut trailer here

Aesi, Tyrant of Gyre Strait Benthic Anomaly Benthic Behemoth Biolume Egg Biolume Serpent Bladecoil Serpent Bog Serpent Caetus, Sea Tyrant of Segovia Cryptic Serpent Deep-Sea Serpent Deep-Sea Terror Denizen of the Deep Dirgur Nemesis Dreamwinder Floodtide Serpent Frilled Sea Serpent Gearseeker Serpent Harbor Serpent Iceridge Serpent Junk Winder Koma, Cosmos Serpent Koma, Cosmos Serpent Koma, World-Eater Kukemssa Serpent Lava Serpent Lightning Serpent Loch Mare Lochmere Serpent Marjhan River Serpent Ronom Serpent Sandbar Serpent Scrapdiver Serpent Sea Monster Sea Serpent Serpent of Yawning Depths Serpent of the Endless Sea Serpent of the Pass Shoal Serpent Shrouded Serpent Slinking Serpent Slipstream Serpent Sliptide Serpent Spire Serpent Steelclad Serpent Striped Riverwinder Sword Coast Serpent Taniwha The Terror of Serpent's Pass The Unagi of Kyoshi Island Tolarian Serpent Tolarian Terror Verazol, the Split Current Vodalian Serpent Wormhole Serpent Xolatoyac, the Smiling Flood Yorion, Sky Nomad

Dragonlord Silumgar Sower of Temptation, but bigger and scarier
Will can only discount generic mana costs
If a Necrodominance you control is destroyed by a spell you own, Necrodominance will be exiled and then the spell will be put into your graveyard
It wants tons of tiny little bodies to be buffed by big mana creatures that are sacrificed by The Meep