Mission 54: Eliminate the Dual Blade

Mission 54 in Kingdom Hearts 358/2 Days is an optional mission from Axel that requires Roxas to eliminate a Dual Blade that has appeared in Halloween Town.

Regular mission
Eliminate the Dual Blade.

Story summary
Roxas tackles the Dual Blade in Halloween Town.

Mission walkthrough
Before accepting the mission, equip a lot of Thunder magic to deal with the boss in a more effective manner. If you want to speed the process up, come back later with Thundara and Thundaga magic. Move to the right of the starting point and jump to grab the Unity Badge. Then follow the path straight defeating Heartless and unlocking a chest to obtain a Gust Shard. Once you reach the town square, the Dual Blade will instantly charge at you. Either defeat the Dual Blade, then search the area for treasures or vice-versa. Glide over top of the well to obtain the Ordeal Badge, then continue straight to reach the Ordeal Blazon. To the right of the Ordeal Blazon (hidden behind the wall) you will find a chest containing an Aerial Recovery LV+(L). After you have cleared the area, its time to RTC.

Video
Video walkthrough here.