Duuuuuude, that'd be awesomeNot sure about ALL of them, but we still don't have a Poison/Steel type. Poison/Steel with Levitate would have only one weakness, which would be Fire. Incoming mechanical scorpion tank who's Mega Evolution causes it to lift off the ground harrier jet and gain the Levitate ability.
How about an Electric/Poison-type in the form of a battery leaking acid?