The copies are created on the stack, so they're not "cast." Creating a copy won't cause abilities that trigger when a player casts a spell to trigger
I dont recommend them for typical Arena users

Domri, Chaos Bringer Doomskar Warrior Dovin, Grand Arbiter Draconian Cylix Dragonologist Drastic Revelation Drawn from Dreams Dreamshaper Shaman Duelist's Flame Duelists' Convocation International (playtest) Dwarven Strike Force Din's Company Eclipsed Boggart Eclipsed Elf Eclipsed Flamekin Eclipsed Kithkin Eclipsed Merrow Eight-and-a-Half-Tails Avatar Elkin Lair Ellie and Alan, Paleontologists Ellyn Harbreeze, Busybody Ellywick Tumblestrum Elspeth Resplendent Elvish Rejuvenator Emergent Woodwurm Empty the Laboratory Endurance Enigma Sphinx Enigma Sphinx Avatar Enlisted Wurm Etali's Favor Etherium-Horn Sorcerer Ethersworn Sphinx Evercoat Ursine Evolutionary Leap Exalted Flamer of Tzeentch Expand the Sphere Explore the Vastlands Explosion of Riches Faceless Agent Farsight Ritual Feral Encounter Fervent Mastery Fight Rigging Fireflux Squad Flamekin Herald Flametongue Kavu Avatar Flay Florian, Voldaren Scion Floriferous Vinewall Flowstone Flood Follow the Lumarets Fomori Vault For the Ancestors Forceful Denial Forging the Anchor Fossil Find Foundry Beetle Fragment Reality Franklin Richards, Ascendant Free-for-All Freestrider Lookout Frenetic Ogre Freyalise, Skyshroud Partisan Friendly Fire Frontier Seeker Furnace Layer Gallia of the Endless Dance Gamble Garbage Elemental Garruk's Harbinger Geist of Regret

Shading and Backgrounds : Add shadows under the Pokmon to make them stand out
Having all your creatures dodge spot removal is a pretty sweet advantage
Boros Energy decks in Modern have long used Seasoned Pyromancer as a way to sculpt their hands and put stats on the board