Fire Emblem: Path of Radiance/Chapter 11: Blood Runs Red

After freeing the prisoners, the group discovers that Elincia's retainer's are still alive. This news lifts the morale of princess Elincia and the group marches on towards Port Toha. After arriving the group are troubled by the fact that the residents of Toha are not worried about the daein army even though they lost the war. Despite this, they continue preparations as normal and Ranulf goes to find a captain to take them to Begnion. Once he does find one, however, daein soldiers appear and prevent anyone from leaving or entering the town, preventing the mercenaries from escaping. Despite this they plan to continue onward, but before they do so a women discovers that Ranulf is a laguz and sounds the alarm. Ranulf is immediately beaten repeatedly, Ike goes to help but this arouses suspicion in the residents and they alert the Daein soldiers and tell them that there are some suspicious folk (the Greil mercenaries). The Daein army, accompanied by some vigilantes, attempt to intercept and kill the greil mercenaries, this forces them to fight their way to the port.

Base preparations
Replace any worn out weapons with newer versions or the items you received from the chests last level. If you killed the boss you should have got a master seal, if Rhys or Soren are trailing behind the others, use bonus experience to make sure they are at least Lv15 and then make that unit use the master seal, this should allow them to get the boost they need to become a bigger part of the group. If it was Rhys you just promoted then buy him a light tome from the armoury if you can.

Use Bonus experience to help Rhys and Soren catch up with the rest of the group (or Vice versa). Give them any skills you wish, watch any info or support conversations you want and then save the game. Once you are ready, you may start the mission.

Walkthrough
If Oscar's a paladin by the start of this level, place him on the top-left square (closest to the western house) If he's not one, place Titania there instead. Then position Boyd on the bottom right square (closest to the southern most house.) Make sure you use lethe and position her on the top-right square (closest to the vigilantes.) Once you've got that settled, save and start the mission.

Make Oscar (or Titania) plug up the gap in the fence which enables the enemies to reach the house. Then make Boyd visit the southern-most house to get a dracoshield. Once this is done, use Titania (or Oscar if he's not a Paladin), Soren, Ike and Volke to defeat the closest enemies and finally send lethe up north to defeat a vigilante, end your turn here.

At the start of the enemies turn, Zihark should run over and talk to Lethe, he should join your squad. Once the rest of the enemy has finished, turn two should begin. Use Zihark to defeat all of the vigilantes (on his own) while making Lethe retreat to the southern-most house. Use Oscar (Or Titania) to defeat as many enemies as possible and then send Soren, Ike and Titania (Or Oscar) in as reinforcements. Once those enemies have been cleared up and the ones near the southernmost house have been too make the group regroup at the crossroads (remembering to take the elwind from the easternly house). Then use Zihark to defeat the nearby knights and visit the house, where he'll receive a killer Lance. At this point leave him where he stands for the rest of the level.

Once the group is all together, put Boyd with a hand-axe on the edge of the enemy bosses zone, heal him to full health if he is running low on it. The next turn, the enemy boss should come running down and attack Boyd with a bow, hopefully, Boyd will survive this attack. Once you have engaged the boss, the Black knight will appear, do not attempt to engage him with Zihark as anyone who does battle him will be killed. Ignore the Black Knight's threat as he does not move unless you are foolish enough to enter his attack range. Use Soren and boyd to defeat the Boss by attacking in a square adjacent to him. If they don't finish him off, finish him off with Oscar.

The rest of the enemies should be quite easy for your group, kill the knight on the square with Soren or Boyd and then arrive and complete the mission.