373 cards found matching energy cost is at least 4

Xerath, Freed
Yasuo, Remorseful
Yasuo, Windrider
Yeti Brawler
Yi, Honed
Yi, Meditative
Yone, Blademaster
Yordle Explorer
Zaunite Bouncer
Zed, From the Shadows
Zed, Without a Sound
Zephyr Sage
Zilean, Time Mage