15 cards found matching power cost is at least 3

Atakhan
Baron Nashor
Cataclysmic Duel
Commander Ledros
Elder Dragon
Grand Strategem
Icathian Rain
Master Yi, Unstoppable
Mystic Reversal
Needlessly Large Yordle
Possession
Premonition
Sivir, Ambitious
The Ruination
Time Warp