The Lightning Hammer is a weapon obtained by trading a Black Ninja Robe (BNR) to an NPC in Maeling Town.
Requirements
Access to Maeling -3
Ability to kill BNR ninjas
Walkthrough
Head to Maeling -3 and kill ninjas until you find one wearing a Black Ninja Robe (BNR).
Return to the center of Maeling Town and locate the NPC holding a Lightning Hammer.
Hold the BNR in your right hand while standing on the trader's hex.
Click on his name, then click the talk button. He trades his Lightning Hammer for your BNR.
Rewards
Lightning Hammer
Tips
An Improved Lightning Hammer can be obtained by bringing a Lightning Hammer and a corpse of a Kinzo to Mingot in south Maeling.
An Improved BNR can be made by bringing a BNR and a piece of Fine Jade to Bakoru east of Maeling (behind steps to Maeling-1) — improves the agility bonus.