Challenge Restrictions:
1. No level grinding:
-No Tower of Valni
-No Overworld Map Encounters
-No Arena Battles
-No "Boss Abuse"

2. "Low Tiers" Only
I'll only be using Eirika and a selection of mediocre units. As of this video, the army's roster contains:
-Eirika
-Gilliam
-Ross
-Colm
-Neimi
-Natasha