The Sky Storm Liger is a super-rare Box Weapon that possesses the special traits of both the Sky-attribute Leone di Cieli and the Storm-attribute Tigre Tempesta. However, it is speculated that this Box Weapon was originally the "white Sky Lion", while the Ligre Tempesta di Cieli is thought to be its mutated figure caused by Xanxus mixing in the Flames of different attribute that he can emit due his unique constitution when injecting Flames in the Box. Xanxus calls it "Bester".