From the Super Mario Wiki
Boomer is an honorable sword fighter and a member of the Smithy Gang in Super Mario RPG: Legend of the Seven Stars. After Smithy's forces occupy Bowser's Keep, Boomer is placed in charge of the new base.
After Mario fights his way past Smithy's minions, Boomer challenges Mario's party to a duel on chandeliers, the same chandeliers on which Mario fights Bowser at the beginning of the game. In battle, Boomer wields a katana and has the ability to power up his defense and offense. After being defeated, apparently suffering from a heart attack, he severs the rope holding the chandelier he is on and plummets to the ground (although the Chandeli-ho implies that he survived the fall), allowing Mario and his party to pass unhindered to the giant sword Exor.
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