Brainiac | Boss Fights and Tactics LEGO Batman 3 Guide

Brainiac boss fight appears in the mission Europe Against It. First, deal with Brainiac's henchmen. For this you should preferably use Superman to save yourself from being hurt by Brainiac. Once you have dealt with the henchmen, use the resulting bricks to create a mirror. Approach the mirror and turn it at Brainiac's direction.

Repeat that step thrice. When Brainiac's ship lands on one of the buildings, fight off some more henchmen and use the resulting bricks to create mirrors that will deflect the beam into Brainiac.