Narin appears to the party if you have the Red Prince with you and immediately attacks after a small bit of dialogue.
You'll find Narin where the player party icons are on the map above.
Narin will approach The Red Prince once he is in range so what you can do is put him alone to walk up into the area and re-position the rest of your party elsewhere for an advantage. I've found, however, that he will target the group if they are close enough.
Narin will always open with Throw Dust into Oil Flask, he will follow that up with Invisibility if he has enough AP.
Once he reappears he will cast Burning Blaze at your party so use your turn to re-position them outside of the Oil Field right away or else the party will suffer massive damage.
Narin inflicts constant Blindess with Throw Dust, keep your party spaced apart to avoid getting clustered blinded by him. If you have Burn My Eyes on a Pyromancer character that can also clear Blinded from one target.
Fortify : Restores Physical Armor, cures Poisoned, Bleeding and Burning, it also makes the fortified character unable to be teleported.
Throws Oil Flask
600 party wide Experience.
Dialogue with The Red Prince