Argeia

Also known as the White Succubus before her name is discovered, she is the first succubus encountered in the game, and only succubus encountered in the prologue.

When the protagonist becomes an Adalon Hunter, she can be found in a house, north of the river in the Vivid Forest, along with her friend Drita.

In chapter 3, Argeia is revealed as the oldest "daughter" of an incubus known as the God of Gifts.

It is worth noting that even though the protagonist and Argeia met up to three times depending on the routes selected, none of the encounters have resulted in combat.

Strategy
Since she cannot be fought, there is no combat strategy for Argeia currently.