This is an easy fight. Basically the same as Druid/Warlock, except easier. Play it as Druid/Warlock. The only thing that they really do differently is put Curse of Tongues on Neth, to combat the free Mana Drains (no ability to avoid it as a Paladin, except cleanse, which, when Feared, is impossible). Persevere with it until the Paladin uses his bubble. When he does, switch to the Warlock for the duration of it, then switch back to the Paladin, Bloodlust, finish draining him. Easy win.

Obvious tips:

• Curse of Tongues on both. Use Frostshock on the Paladin to avoid him running away from Neth. Purge the BoF.
• LoS their Warlock as much as possible. Tremor Totem whenever Neth gets Feared - it completely negates their CC.
• Warlock Perspective: If you notice their Paladin isn't keeping up on the pet well, put your autodevour on and set the pet to their Warlock. If it dies and he doesn't throw up a fake buff before trying to Fel Domination a new pet, you'll snag the Fel Dom. The Paladin shouldn't be getting away from you anyway due to Fear, CoEX, and DoTs keeping him in combat.