1. SG
2. 1-3 Battle for Edogawa

Despite being the first boss, this flying potato doesn't hit much harder than other enemies. It does, however, hit a large area around its target at the same time. Use units with varying range or use strategies to send them to the north and south in order to avoid getting your whole team dinged.

Shotguns are safe. HGs and SMGs should also be able to dodge with relative ease.

Any mid-range unit should be safe, but they'll get hit by splash damage if the boss targets a close range unit. There's also little point in sending LMGs here since there's only one enemy and you can train them more efficiently in area two where the experience is better.

They'll be far enough away from your frontline to avoid splash damage and even your blindest AMR should have no problem hitting the boss.