Battle Against the Masked Man is the last battle theme in Mother 3, playing when Lucas is fighting against the Masked Man at the end of the game. This theme is rather weird; it consists of several pulsations with some miscellaneous instruments and sound effects in the foreground. The only time in which the player can hit the Masked Man in an attempt to combo is after Flint is struck by PK Love.
- This is the only battle theme that does not have a heartbeat track. The Masked Man's other theme, Strong One (Masked Man), also has no defined heartbeat, but it automatically defaults to the original Strong One heartbeat.
- It is possible that this is connected to Claus' condition; the song's beat is the enemy's heartbeat, and Claus is mechanized. Claus' heart is mentioned on Tanetane Island.
- If one pays attention, they can hear bits from other battle themes, such as sped-up and slowed down piano sections from Mambo de Battle, and an eerie-sounding rendition of the Mother 3 Love Theme.