Meet The Robinsons Defeating the guardian robot
Hit both activator switches with matching colors. Then, hit the generator lens that the pipes lead to. Repeat this process until the next part. This time there is one more generator lens, and the guardian will have another move. Do not get close to a target. Repeat the process until the robot is defeated.
The image featured at the top of this post is ©The Legend of Heroes: Trails of Cold Steel III key art / Original