Mission 66: Restore the town's Heartless

Mission 66 for Kingdom Hearts 358/2 Days sends Roxas to solve the mysterious disappearance of the Heartless population in Halloween Town.

Regular Mission
Restore the Town's Heartless by defeating the Leechgrave.

Story Summary
Roxas is sent to Halloween Town to find out what happened to the Heartless population, which leads him to an encounter with the Leechgrave Heartless that seems to "eat" other Heartless.

Mission Walkthrough
Set plenty of Fire panels prior to this mission, along with many Hi-Ethers. Entering the Halloween Town Square, Roxas sees where all the Heartless have gone. The town is now "infested" with Tentaclaws and Roxas must defeat all of them in the square before he can proceed. Quite soon Roxas'll figure out that wiping them out by using aerial combos takes a very long time. Casting Fire spells from a distance takes them down much more quickly, but conserving magic for the upcoming boss fight is more important.

Video Walkthrough
Video walkthrough here.

Trivia

 * FinalMix+ discovered a glitch in this mission. After defeating the Leechgrave in Mission Mode and jumped out of the drain outside the Manor Ruins as dual-wield Roxas, he fell right through the wall and died. Auto-Life didn't save him.