My puppy actually sat next to me when I slayed Belial two nights ago on Diablo III. It was an interesting boss fight as that Prime Evil had two forms to contend with. The first form engages you in battle after sending his minions at you. Upon pummeling him to about 10% of his health, he’ll change size (lol…much like those monsters in Japanese henshin series…they grow way..way..bigger).
In his uber-large form, he is largely stationary, save for his arms. He’ll use them to pummel you ala King Kong (you’ll notice a green spot on the semi-circle arena level where he’ll land his arm (or both arms). The second attack is some sort of green flame…just stay away from the center of the level. The third form of attack is a whole bunch of green spots appearing and exploding..just keep on moving.
I had a Templar follower dealing damage to Belial all the while I’m running around. Thank goodness for single-minded AI companions. Total number of tries before I figured out Belial’s pattern of attack: 3.