I am Setsuna | Aeterna's Legendary Spritnite: Gearadia

With Aeterna in your party, go to Tenderville and walk straight and head into the first house. Speak with the man and he will ask you to go to an island.

Find the Island of Misfits on the southeast corner of the map and you'll find a city called the Nameless Village.

Once you enter the city, head to the house on the left and speak to the old man. Leave the house to trigger another conversation. Then, go to the lookout tower and you will see a big sheep monster. After you're done, go back to the old man's house, have another conversation and leave him and try to leave the village. You will encounter with the monster, but there will be no battle. The monster dies later and then go back to the old man.

After that, head back to Tenderville and speak to the man in the first house again and you will get Gearadia spritnite.