This deck does not appear to be legal in Standard (Season from Sep 2021).
Problems: You cannot play more than 4 of: Aether Gust, Blacklance Paragon, Bonecrusher Giant // Stomp, Brazen Borrower // Petty Theft, Casualties of War, Cauldron Familiar, Cavalier of Flame, Cavalier of Gales, Deafening Clarion, Devout Decree, Drill Bit, Duress, Embercleave, Embereth Shieldbreaker // Battle Display, Epic Downfall, Fervent Champion, Fires of Invention, Gilded Goose, Growth Spiral, Gutterbones, Hydroid Krasis, Knight of the Ebon Legion, Lovestruck Beast // Heart's Desire, Mayhem Devil, Midnight Reaper, Murderous Rider // Swift End, Mystical Dispute, Nissa, Who Shakes the World, Noxious Grasp, Paradise Druid, Rotting Regisaur, Sphinx of Foresight, Stormfist Crusader, Teferi, Time Raveler, Thrashing Brontodon, Tithe Taker, Trail of Crumbs, Wicked Wolf, Witch's Oven. · Not legal in this format: Aether Gust, Beanstalk Giant // Fertile Footsteps, Blacklance Paragon, Bonecrusher Giant // Stomp, Brazen Borrower // Petty Theft, Casualties of War, Cauldron Familiar, Cavalier of Flame, Cavalier of Gales, Cavalier of Night, Cavalier of Thorns, Chemister's Insight, Claim the Firstborn, Deafening Clarion, Devout Decree, Dovin's Veto, Drill Bit, Edgewall Innkeeper, Embercleave, Embereth Shieldbreaker // Battle Display, Epic Downfall, Escape to the Wilds, Fae of Wishes // Granted, Faerie Guidemother // Gift of the Fae, Fervent Champion, Fires of Invention, Frilled Mystic, Giant Killer // Chop Down, Gideon Blackblade, Gideon's Sacrifice, Gilded Goose, Growth Spiral, Gutterbones, Healer's Hawk, Heraldic Banner, Hunted Witness, Hushbringer, Hydroid Krasis, Infuriate, Justice Strike, Kenrith, the Returned King, Knight of the Ebon Legion, Korvold, Fae-Cursed King, Lava Coil, Leafkin Druid, Legion's End, Light Up the Stage, Lovestruck Beast // Heart's Desire, Loyal Pegasus, Lucky Clover, Massacre Girl, Mayhem Devil, Midnight Reaper, Murderous Rider // Swift End, Mystical Dispute, Nightpack Ambusher, Nissa, Who Shakes the World, Noxious Grasp, Opt, Paradise Druid, Priest of Forgotten Gods, Quasiduplicate, Quench, Questing Beast, Raise the Alarm, Rankle, Master of Pranks, Risen Reef, Ritual of Soot, Rix Maadi Reveler, Rotting Regisaur, Runaway Steam-Kin, Shifting Ceratops, Shimmer of Possibility, Sinister Sabotage, Solar Blaze, Spawn of Mayhem, Sphinx of Foresight, Stormfist Crusader, Teferi, Time Raveler, The Great Henge, Thought Erasure, Time Wipe, Tin Street Dodger, Tithe Taker, Trail of Crumbs, Unbreakable Formation, Venerated Loxodon, Vraska, Golgari Queen, Wicked Wolf, Witch's Oven, Witch's Vengeance.