304 cards found matching energy cost is at least 4

Whiteflame Protector
Wildclaw Shaman
Wily Newtfish
Wizened Elder
Wraith of Echoes
Xerath, Freed
Yasuo, Remorseful
Yasuo, Windrider
Yeti Brawler
Yi, Honed
Yi, Meditative
Yone, Blademaster
Yordle Explorer
Zaunite Bouncer
Zephyr Sage
Zilean, Time Mage