What about a wand that lets you summon your school tree as a minion?
Fire - Staff of the Volcanic Tree Storm - Wand of the Cloud's Trunk Ice - Rod of Snow's Roots Myth - Staff of the Cyclops Tree Life - Wand of Peace's Tree Death - Skeletal Tree's Rod Balance - Tree of the Scale's Staff
Respectively, they summon Bernie, Torrence, Kelvin, Ivan, Blossom, Mortis, and Niles
Idea 2: New Bosses
I read a post awhile back about a clockwork world. What if the main bosses were as follows