Mission 14: Eliminate the Darkside
A Darkside has surfaced in Twilight Town. Team up with Xion, find it, and eliminate it at once.
After they arrive in Twilight Town, Xion speaks again and uncovers her face for the first time. The two successfully approach and confront the Darkside Heartless. After the battle, the Darkside attacks Roxas, tossing him and his Keyblade away. The Keyblade falls in front of Xion, who picks it up and with a quick slash, finishes off the Darkside. Impressed and feeling a connection with Xion, Roxas brings her up to the clock tower and gives her some sea-salt ice cream, just as Axel had with him.
Entering on the Side Street, clear out the lesser enemies and make your way to Station Heights, being sure to grab the two chests in the area. Do the same at Station Heights as you make your way to the Station Plaza for the main confrontation.
Kingdom Hearts veterans should have no problems fighting Darkside. It uses the same strategies It has in any other game. Before you begin the battle proper, make sure you snag the lone chest to the right of the Station entrance, as you will RTC when the battle is over.
Avoid all battles as you make your way to fight the Darkside. Stocking many magic casts and carefully studying its attacks will help you get through the battle without getting hit. As the Mission Intel indicates, be sure to equip Guard to help protect you.
Again, skip all non-essential battles and head directly for Station Plaza. Attack the Darkside's hands whenever possible, and strike its head whenever it bends forward to cause extra damage.
If the battle is still going too slowly, try to pull off a Limit Break to inflict damage quickly.