How can I beat this map?

Like before, my Lysithea only run. The pegasi reinforcements won’t stop spawning until that guy in the back is killed but I can’t get to him. My rules are that units other than Lysithea that aren’t required to be on the field aren’t allowed on the field, and Blue Units (except Lysithea) aren’t allowed to do anything except use consumables. They can be attacked but can’t counterattack, they can’t use magic on Lysithea, etc.

I think one or both of these rules might need to be broken for this map.