It depends. Vaporeon if your team doesn't have outstanding weaknesses to Electric and you can be more defensive, Goodra if you want to be more offensive and your team doesn't have outstanding weaknesses to ice or fairy.
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Dragon Pulse/Draco Meteor, Rest, Infestation/Sludge Wave, and Rain Dance
Infestation really helps if you want to trap someone for at least two turns. Rain Dance puts the weather back up in case of Ninetales or Tyranitar. Sludge Wave is a good fairy counter, and the STAB Dragon moves depend on whether or not you like to switch out Goodra.