A clever girl who, while she yet lived, was transformed into an undead type Child with no will of her own. Unknown then unexpectedly fell into a deep slumber from which she cannot wake. She dreams of when she was a human, days when she lived happily alongside Bathory.
Auto attack: 
Deal 71 Auto Attack Damage to the target (Automatic)
Deal 206. Heal 218 HP for 1 Ally with Lowest HP
Deal 379 Damage, Heal 866 HP for 2 Allies with Lowest HP, Debuff EVA +15% for 12 seconds
Deal 854 Damage to 2 random Enemies, 80% chance to remove 1 Debuff from 3 Allies, Heal 1102 HP for 3 allies with Lowest HP
Debuff EVA +8% for Dark Type Allies
Preferred Soul Carta
Drive Skill Voice
It's alright. I'll protect you.
One. I swear to be your faithful companion as long as I live, Bathory. I will always serve you. Nothing will cause me to leave your side.
Weak Point Attack Voice
I won't forgive you, demon.
Critical Attack Voice
Ashes to Ashes
Inner Voice I
My name is... My name is Theresa. No, wait, Unknown? No, I...
Hah. Hah. Eheheh.
Let us return. For though we walk through the valley of darkness we fear not calamity.
Battle Start Voice
Let us go. To the valley of darkness.
Hot Spring Voice
Urgh... Is this hell? Or no, heaven?
Inner Voice II
I've lost...my eternal companion. Where? Where am I?
Slide Skill Voice
Who am I?
*sigh* Is this a dream?
Almighty god, bestow upon us your mercy, forgive our sins, and lead us to eternal life.
Inner Voice III
Sayoko...let's meet again...someday. Don't worry. We'll meet again, for sure.