Heart Seal Locations & Uses
The Heart Seal in Fire Emblem Fates: Revelation is a versatile item that allows a unit to change into any *base class* that the unit itself has previously held or has access to through its innate class options. This is distinct from other Seals that rely on partner or friendship bonds. The Heart Seal provides a significant degree of freedom in unit customization, enabling players to re-specialize a unit if their initial class choice proves suboptimal or if they wish to grant the unit access to a different set of skills or weapon types. For instance, if a unit has previously been a Fighter and then promoted to a Berserker, using a Heart Seal would allow them to revert to the Fighter class. Furthermore, if a unit has access to multiple base classes through their lineage or other mechanics, a Heart Seal can be used to switch between those available base classes.
The source material does not explicitly state the locations where Heart Seals can be found in Fire Emblem Fates: Revelation. However, it is a common convention in Fire Emblem games for such flexible items to be available through various means, including purchasing them from shops (potentially the StreetPass or MyCastle shops), as rewards for completing certain side missions or paralogues, or as drops from specific enemy units. The "General FAQs/Guides" are the most likely place to find precise details on the acquisition of Heart Seals. Given their utility in re-shaping a unit's class, be on the lookout for opportunities to acquire them, as they can be instrumental in adapting their army to challenging encounters or correcting earlier strategic missteps in unit development.
The primary use of a Heart Seal is to change a unit's current base class to another base class that they have access to. This is not a promotion to an advanced class; rather, it's a change within the base class tier. For example, if a unit is a Villager and has access to the Fighter and Mercenary base classes, a Heart Seal could be used to switch them between these two. If a unit has already promoted, using a Heart Seal would revert them to their original base class before promotion, allowing them to then choose a different promotion path with a Master Seal. This is a powerful tool for correcting mistakes or for players who wish to explore different skill sets for a unit. The "Fire Emblem Fates Class Promotion Chart" is essential for understanding which base classes a unit can access, and what advanced classes are available from those base classes after a Heart Seal has been used to switch to a desired base class.