Battle Chasers: Nightwar

Story related, can not be missed.

When you reach Junktown, you will need to find the three parts to the password to get you into the depths of it. Search around the area for the password parts and then return to the beginning and give them the password to be granted entrance inside. Once inside, ride up the circular platform and into the boss fight against Wargolem Lancer, a giant mech golem. He is very powerful, so you will want to make sure that you are healing as much as possible after his attacks. He also has a high defense, so this battle will take a little while. Once you defeat him and end the dungeon, the trophy will pop.