If forced to put Mew ex in the active spot to start, you have a few options to help keep it alive long enough to attack
Marvel, Elastic Ally Nakia, Wakandan Operative Okoye, Mighty and Adored Pet Avengers Power Pack Reptil, Dinomorpher Scarlet Spider, Ben Reilly Scions of the Ur-Spider Shang-Chi, Martial Mentor Shang-Chi, Master of Kung Fu She-Hulk, Attorney-at-Law She-Hulk, Jade Defender Shuri, the Black Panther Silk, Web Weaver Spider-Girl, Legacy Hero Spider-Ham, Peter Porker Spider-Man India Spider-Man, Brooklyn Visionary Spider-Man, Miles Morales Spider-Man, To the Rescue Spider-Rex, Daring Dino Spiders-Man, Heroic Horde Stature, Young Avenger Storm, Force of Nature Storm, Queen of Wakanda Storm, Shaker of Skies Storm, Windrider Surris, Silk-Tech Vanguard T'Chaka, Venerable King T'Challa, the Black Panther Tarantusk, Unwisely Awoken The Astonishing Ant-Man The Clutter Cluster
Thats massive if the energy deck can stand to add graveyard synergies
Are you already playing Jaces Ingenuity