Anything that can work well with rains is what I do as a corr
Fire, Ice, Water and Storm. I skip Hurricane and Gale and with power recoloring you can get some light orange fire to really light up the place
Fire, Ice, Water and Dark
Fire, Ice, Water and Trick Arrow - Get the Taser power from the pay to win vendor to ignite oil slick whenever you or someone else cant. Prestige Attack or whatever its called
Fire, Ice, Water and Time
Fire/Storm is my highest level
My Ice/Trick is also climbing high because stacking 3 rains is fun
And Water/Time is also getting up there in vet levels.
And my Time/Fire defender is my last defender ever because its just that god damn fun.