Enter Eldieme Necropolis from G-8 in Batallia Downs. Walking down the stairs you will find a ??? at (F-9). There will likely be a Gazer nearby, which will aggro a level 52 character, and will also aggro your friend during the battle if it is too close. It's best to kill the Gazer before you examine the ???.
Examine the ??? and Namorodo will spawn. During the battle, your friend will appear and assist you.
After you and your friend defeat the NM, talk to your NPC friend. He/she will tell you he will help the little girl get back to Jeuno and then disappear. If you wait too long, your friend will disappear anyway and you will have to fight Namorodo again.