How to Complete Crying Eyeball
In this quest, you need to prevent the enemies from reaching the squares in front of the mine entrance. Unfortunately, all of these enemies can fly, so you can't use your units as a wall between the enemies and the mine entrance, since they can just fly over you. There aren't enough units to stand on all of the mine entrance squares, either.
The enemies in this quest are Floating Eyes, Ahrimans, Plagues, and Bloody Orbs. When you kill them, more will randomly appear. Ahrimans and Plagues can inflict Confuse, and Ahrimans can use Roulette, possibly killing a random member of your party.