I can't believe I haven't seen this topic!
Anyways here's my deck.
Rifle: water rifle
Hammer: ice hammer
Cane: fire stick
Gauntlet: oil thingie
Pistols: riverter pistols
In battle, I use the water ice combo, oil fire combo, and riveter pistols if they are charging. I don't use starter pistols (even though they are one of the best) because I already have a fire weapon that does a bit of damage and sets them on fire.
Just remember, you have to battle smart. Think about your teammates. If they normally use water, don't use fire. Use what they use to your advantage or support them with your weapons. If not, then you will do a lot less damage.