Maybe a Zebstrika Crest that gives it an OP physical electric move
A Magikarp Crest that gives it the power of Gyarados but needs to be at a certain level to use this power
Toxtricity Crest???? gives more speed on a electric terrain or power plant setting
Sirfetch'd Crest makes moves relating to the leek blade, eg: Leaf Blade or Night Slash, more powerful: and a boost for Swords Dance
Snom Crest, makes it better than Frosmoth but requires high pokemon level, and high friendship level