Mist beats Fear
EMP Beats Death
Lava beats Antarctic
Bosses without a weakness
Scorpio
Libra
Chemical
Blade
Scorpio: Poison Needles
Libra:  still thinking of one
EMP: Thunder Shield
Blade: unknown
Chemical: Toxic Claw
Mist: Icy Wind
Fear: Fear Blade
Lava: Flame Blast
Antarctic: Ice bomb