At the base, first make sure you read the info conversations to get Volug. He is a very powerful unit at this part of the game. You will also be able to receive 10,000 gold for free. Use this money to buy any valuable items you may want at Aimee's shop. Forge a new lance for Aran if you have not already because the iron lance and steel lance are all you can get at this point. Use bonus experience on Meg to get her to at least level 6. Replace any old weapons, and now you are ready.
The Battle[edit]
Position Aran to where he can attack one of the myrmidons. Position Leonardo so he can shoot the nearest Fighter and Edward can kill him with a sword. Volug can take out any of the enemies on his own. Move Sothe to a spot where he will be attacked by the two mages below you and equip a throwing knife. Make sure the soldier cannot attack you. Get Laura and Micaiah out of harm's way and end the turn. The next turn, the enemies in front of you will probably try to kill Leonardo. He won't die unless you completely neglected him earlier in the game. The mages will attack Sothe and he will kill them with his knife. The next turn, use Sothe to steal a master seal from the soldier. Kill any enemies near you while positioning your team next to the ledge so that enemies can't hop down and kill you.
On the enemy turn, the soldier will attack Sothe and Sothe will probably kill him. Enemies will run up to the edge of the ledge but do nothing. On your turn, will one ledge enemy with ranged attacks. Then, move Volug to the top of the ledge to take out the guy with a hand axe.send anybody who is not guarding the ledge to attack any new reinforcements. Once all nearby enemies are killed, slowly advance turn by turn near your allies. Soon, you will have defended long enough and the level is over.