At first, Tlaloc will shoot blasts at Dead Juju, Lok, and Jibolba. Run over to Jibolba and press Circle to switch bodies. Then, kill all the Nightmare Creatures. Next, switch with Dead Juju and do the same thing. Then, switch with Lok and do the same thing again. Then, Tlaloc will lose his barrier. Attack him. Tlaloc will now change strategies. He will send Nightmare Creatures at your friends. Kill them all, then attack Tlaloc. Keep repeating this process until Tlaloc is defeated.