Garchomp would be a great one for this. Give it moves like Swords Dance, Dragon Rush, Earthquake and Fire Blast/Stone Edge/Iron Tail depending on which one you like and have Ninjask use Hone Claws. This would be made much more effective if you mega evolve Garchomp.
Dragon Dance users like Salamence and Gyarados would also be good choices so you can free up a move slot and replace it with another coverage move.