The boss will perform a pair of melee attacks at a distance that will fire out a wave of energy. Towards the end of the fight, this slam attack will also cause energy swords to fall from the sky randomly around the boss which you will need to avoid. The Commander will slam his shield into the ground, stunning you if you are too close. You will need to dodge or block to avoid the successive swings.
The boss can perform between a 1 and 2 hit combo depending on your proximity to him.