373 cards found matching energy cost is at least 4

Kharox
Kha'Zix, Evolving Hunter
Kha'Zix, Mutating Horror
King's Edict
Kinkou Lifeblade
Kinkou Monk
Laurent Duelist
LeBlanc, Everywhere at Once
Lee Sin, Ascetic
Lee Sin, Centered
Leona, Determined
Leona, Zealot
Lillia, Protector of Dreams
Lord Broadmane
Lux, Crownguard
Lux, Illuminated
Machine Evangel
Maddened Marauder
Maduli the Gatekeeper
Mageseeker Investigator
Mageseeker Warden
Magma Wurm
Malzahar, Fanatic
Masa, Crashing Thunder