373 cards found matching energy cost is at least 4

Irelia, Fervent
Irelia, Graceful
Iterative Design
Ivern, Friend to All
Ivern, Nurturer
Jae Medarda
Jaull-Fish
Jax, Unmatched
Jax, Unrelenting
Jayce, Brilliant Inventor
Jayce, Hammer in Hand
Jayce, Man of Progress
Jeweled Colossus
Jhin, Meticulous Killer
Jhin, Murderous Artist
Jinx, Rebel
Kadregrin the Infernal
Kai'Sa, Evolutionary
Kai'Sa, Survivor
Karma, Channeler
Katarina, Reckless
Kato the Arm
Kayn, Unleashed
Keeper of Law