Instructions
Play through "Fire Emblem: Shadow Dragon's" chapters until you reach Chapter 23: Dark Pontifex. Gharnef will confront you and taunt you before disappearing. To clear the chapter and free Elice, you will need to defeat the illusions Gharnef has created, as well as the Bishop mini-boss who guards the throne.
Fight your way through the illusions that Gharnef has created. Clear the room of enemies in a counterclockwise progression until you reach the upper right-hand corner of the map. The illusions are level 15 Sorcerers with HP 32, but you can easily defeat them with normal weapons, so don't waste resources on them.
Find the real Gharnef and defeat him. Gharnef roams the room, so lure him into position with a strong fighter when you are ready to engage him. Like the illusions, Gharnef is also a level 15 Sorcerer with HP 36. Gharnef protects himself with a powerful shield, but a mage equipped with the Starlight spell can penetrate it, potentially defeating him in a single cast. You will know you've killed the real Gharnef if you receive the Falchion item after the fight.
Kill the Bishop mini-boss and seize the throne to end the chapter. More enemy Sorcerers will appear near the top of the map during turns 7 and 15; time your attack to occur between those turns so that you can fight the Bishop alone. If you engage him while he is isolated, with Gharnef, the illusions and the Sorcerers dead, the Bishop requires no special tactics to defeat.
Speak to Elice at the end of the chapter, when she will appear automatically during a brief cut-scene. After she speaks with Marth about Gharnef's plans, Elice will join the party.