Enhancement is the process of imbuing a Squadmate with addition stat boost through the use of Crystals. Crystals can be acquired through a variety of means. Each stats (HP, ATK, DEF, WIS, and AGI) has a different Enhancement Crystal. 10 Crystals may be used per stats. Only 10 Crystals may be used at a time, regardless of how that 10 is divided. Each Crystal adds 50 Points to the stat for a maximum boost of 500 points per stats.
Using a crystal on a "Source" Squadmate to be used on a "Target" Squadmate will result in the appropriate 5% or 10% of the boosted stats to be transferred to the Descendant Squadmate.
However, using a crystal on a "Target" Squadmate will result in all boosted stats being transferred to the Descendant and all Crysal usage count as well. If 10 HP Crystals are used in a Rank 1 Target, the Rank 2 Descendant will show +500 HP and 10 HP Crystals already used. This boost and count will carry down each time the Squadmate is used as a Target.