This is a pretty tough Scenario to do properly, and I doubt you'll be given the option to kill everyone, including all the troops. Omega's tough, and as soon as he crosses the bridge, Langrisser has it's effect and he becomes even tougher. He has a bow, and the warriors themselves are very difficult to kill, so I usually take Omega straight out with leaders or horsemen.

You'll need to send somebody up to protect the Civilians, too. One of the Generals makes a beeline to the top pf the map to kill the Civilians as they go through, so you'll want to stop that happening. I had a leader (Marie) with a MOV of 10 make it up there, just in time, so don't worry too much. You will be asked towards the beginning a question, which I assume dictates where McLain goes, and what he does. I don't knwo what the answers mean, so I can't help.

Be careful of the Crimson Knights - they're tough, but a strong leader can take them out no problem. Your biggest asset are Archers - I always think so, as you can take people out without getting damaged at all. But especially so in this Scenario, where you are taking on a lot of very powerful generals. Shoot the Crimson Knights before you let anybody else attack them, otherwise you'll need to do a lot of healing.

Your biggest problems start when Rainforce arrives, which is when you kill off Omega. He comes from where you started, and heads towards the bridge. The Royal Lance are really too good for any troops you may have, but they're easy prey for archers. I had Claret block off the first road to the north as they're passing through, taking out the Royal Lance as soon as they got close enough, before picking off the Crimson Knight himself.