Cards like Breach the Multiverse, Expropriate, and Fevered Suspicion are ideal to cast for free, ramp to, or copy
Advanced Search Sets Random Syntax A Real Handful Aclazotz, Deepest Betrayal Aetherborn Marauder Alchemist's Assistant Alchemist's Gift Archenemy's Charm Archfiend's Vessel Ardyn, the Usurper Aspect of Lamprey Assassin Initiate Baleful Ammit Banehound Barrow Naughty Barrowgoyf Blacklance Paragon Blessing of Belzenlok Blood Burglar Blood Glutton Blood Operative Blood Poet (playtest) Bloodline Necromancer Bonepicker Skirge Boot Nipper Butcher's Glee Cabal Initiate Cairn Wanderer Call the Bloodline Cartouche of Ambition Case of the Gorgon's Kiss Cat-Gator Cavalier of Night Chancellor of the Dross Charity Extractor Child of Night Circle of Power Citizen V, Helmut Zemo Comet Crawler Consuming Aetherborn Crossway Troublemakers Cruel Feeding Cutthroat Maneuver Daggerdrome Imp Dashing Bloodsucker Deadly Wanderings Deep-Cavern Bat Depraved Harvester Desperate Bloodseeker Desperate Farmer Doctor Doom, Unrivaled Dreadhorde Invasion Dreamdrinker Vampire Duskfang Mentor Echo of Dusk Egrix the Bile Bulwark Elegy Acolyte Eradicator Valkyrie Escaped Null Essence Infusion Eternal Thirst Evereth, Viceroy of Plunder Exsanguinator Cavalry Eye of Duskmantle Farbog Revenant Fell Gravship Flayed One Flensermite Foggy Swamp Hunters Foot Mystic Galian Beast Gargantuan Leech Ghastly Gloomhunter Gifted Aetherborn
So, with that in mind
At 5 Generic and 2 Black to cast, you will really need some fast mana and protection to be able to both cast Toxrill and not get it blown up
Protection from Spells Emrakul, the Aeons Torn has a lot of text but hidden in it are the words protection from colored spells. A spell is anything currently on the stack
Overlord of Boilerbilges & Overlord of the Hauntwoods These two very powerful enchantment creatures can cheat their mana cost, and if there is anything that is always good in competitive magic it's the cheating of manacosts
