Towns person’s requests are the mini side quests of this game, and they are scattered around Grymoire. The first you’ll run into is from a knight in Cornelia after talking to Princess Sarah the first time. He’s standing by the fountain in the main square, and he’ll have an ‘!’ above his head.
He asks you for an Earth Hammer. These can be found in the Nether Nebula which is, coincidentally, the next place the game is sending you.
While in the dungeon you’ll encounter weight puzzles that have to do with your mirages. The first one has to be done, but as you continue on you’ll see a second one off to the side. Behind it are two treasure chests.
In order to pass this puzzle you must stack a Mandragora and a Copped Gnome, both of which can be found in the Nebula. The Earth Hammer is in one of the two chests.
Return to him after the Goblin attack to collect your reward.