No red units allowed

Use nino with green tomebreaker to bait green mage. After that, use lyn (+atk seal) to kill blue cavalry mage. Fend the other cavalry with green flier of your choice. I choose flier because he/she needs to escape to the water tile to prevent from being killed by celica. Kill alm with lyn and nino, and use blue dancer to tank celica then finish her off with lyn.

Nino

Brave Lyn

Minerva

Performing Shigure