Mission 11: Eliminate the Guardian

Mission 11 for Kingdom Hearts 358/2 Days sends Roxas on another mission with Axel, this time to eliminate the powerful Heartless called the Guardian

Regular Mission
Defeat the Guardian

Story Summary
Axel decides he does not want to waste time in taking out the Guardian; he and Roxas work together to end the threat. However, he drops a bomb on Roxas during their ice cream break afterward. He is being sent to Castle Oblivion, and will not be back for a long time. After Axel leaves, Roxas finishes his ice cream and discovers his stick is marked "Winner".

Mission Walkthrough
Taking a few steps from the entrance in Station Heights triggers a small fleet of Yellow Operas and Minute Bombs. Get rid of them or run past them into the entrance to the Underground Concourse. Minute Bombs are also sprinkled throughout the halls of the Concourse, and are joined by a Watcher on occasion.

Head for exit 3, the one on the western wall, that leads to the Side Street. You will have to open the switches to access the exit; first head into the northern room and operate the yellow switch to open the gate into the southern room. Then, use the blue switch in the southern room to open both the gate in front of you and the one blocking the exit. Finally, defeat the Heartless and open the last gate using the switch blinking pink next to it. Continue out and down the Side Street, continuing to take out enemies along the way. Head for the Sandlot.

The Guardian is basically a big version of the Watcher, and will be accompanied by many of his smaller cousins. Its most damaging attack is a large laser cannon which is easy to see coming; the Guardian will "bow", and a massive blue glow will build in its chest. As the attack will only affect what is directly in front of the Guardian, the beam is easy enough to dodge if you are watching.

Make sure you are ready to go before you fight the Guardian; once it is defeated, you will automatically RTC and cannot explore.

Video
Video walkthrough here.