Fire Emblem: The Sacred Stones (GBA)

This latest entry in the series takes place in the continent of Magi Varl. Demons once populated the continent, but mankind gained piece by sealing the evil forces with five magic stones. Time passed, and the stones became the heirlooms of royal families whose kingdoms divide the present-day continent. The story of Seima no Kouseki begins as the most powerful of these kingdoms, the Grad Empire, begins to invade the remainder of Magi Varl. The Lunes Kingdom, a neighboring kingdom to the Grad Empire, incurs a sudden attack against which it cannot defend, and begins loosing its territory. The Grad Empire army reaches the Lunes Kingdom royal city and the Lunes Kingdom falls. Battles feature submaps which you'll be able to enter and leave at will and there is a new class change system that allows players to select from two upper level classes when the time comes to upgrade.