Caster (Fate/Crossover - Byleth Eisner)

**Caster** (キャスター, *Kyasutā*) is the servant of ??? in the ??? Holy Grail War.

*"I wonder if any students from the academy have made their way here today. I will have to keep an eye out."* — Byleth

For the Saber version; here's the link to **Byleth Eisner**

## Profile

### Identity

Caster's true identity is **Byleth Eisner**, The daughter of Fodlan's legendary mercenary Jeralt the Blade Breaker, and she's a professor at the Church of Seiros's Officers Academy. And when summer came around, she dawns her gorgeous black swimsuit with the purpose to be enjoying a summer away.

### Personality

Byleth has a very subdued personality and has difficulty expressing emotion. As a newborn, she neither laughed nor cried. People she is especially close to, such as Jeralt, are able to tell how she is feeling despite her limited emotional visualizations. A handful of her students note that her outward expressions hardly vary. Some express surprise whenever they simply smile. According to Alois, this trait of hers may in part come from her father, as Jeralt does not show his emotions easily either and can also be difficult to read. This should not be taken as them not having emotions at all however. Due to Jeralt concealing a lot of information about the world, she is showing curiosity about the influence of the Church of Seiros, the mystery of the Crests, and the dynamic of the three nations once she were immersed into the Officers Academy.

Her stoic demeanor slowly changes over the course of the Academy phase. Jeralt notices that she has become more expressive over the first few months, likely a result of the bonds she had formed with their students. Despite appearing indifferent, Byleth can be perceptive of their students and fellow faculty's problems and serve as a great source of emotional support for their issues. As the story unfolds, their emotions become more dynamic including feeling true sorrow, vengeance, and happiness.

Byleth has somewhat of a reputation from her earlier years in her father's mercenary corps for being a fearless and skilled warrior, gaining the moniker of 'Ashen Demon', due to the way she seemingly emotionlessly cut down her enemies in combat. This seems to be somewhat of a sensitive subject for her, as she seem uncomfortable when Hanneman mentions her moniker in her C support. It is notable that in the beginning of the game, Sothis refuses to let the player progress if they do not acknowledge their humanity to her, refuting the "Ghost" and "Demon" options, so it can be inferred that Byleth is uncomfortable with the Ashen Demon moniker because it dehumanizes her.

The three house leaders of the Officer's Academy attest to her martial prowess and have deep, profound respect for her abilities and guidance in battle and in the classroom. She alongside the other students continue to refer to her as teacher or professor even after the time-skip. The three house leaders also deeply regret that Byleth had not chosen their house if she is not teaching theirs, seeing the value in their strengths.

According to both genders of Byleth in Heroes, they do not actually know the distinction between a friend and an ally due to their unusual childhood. Nevertheless, they are well liked by the student body, even those not in in their initial house. Their wisdom ultimately shapes the outcome of the events of Three Houses providing council and guidance to the house leader they chose to teach, helping to shape them into better warriors and leaders.

Several students can develop an interest in them and eventually switch over to their house if not already in them. This results in them also joining her faction during the War, even those from enemy nations defecting to their cause, thus changing their fate. Those who do not join will often express regret facing her in battle. However, some students and faculty members, especially in the Crimson Flower route, will instead express outrage at her, vowing to kill her by their own hands.

According to her profile in Cindered Shadows, Byleth has interests in helping and listening to people, likes swords, reliable allies, smiles, and being trusted, and has no apparent dislikes.

## Abilities

Gifted (A skilled combatant that bested countless opponents during their career as a mercenary and is depicted as a gifted teacher, capable of bringing out the potential within their students and help them excel, even in topics they are not good at. Played an instrumental role in the war, leading their chosen house and army to victory, despite the numerous odds and setbacks that plagued them since Byleth’s abrupt disappearance, ending the war that lasted for five years in a matter of months under their leadership. As a professor, Byleth has profound knowledge in combat instruction, being personally proficient in Sword, Brawling (Martial Arts), and Authority (Commanding a Battalion), with hidden talents in White Magic, though they can also instruct in topics outside of those to almost the same degree. Can potentially become the first leader of the United Kingdom of Fódlan or Archbishop of the reform Church of Seiros).

As a Caster now; Byleth changes her weapon from a sword to Sun's Percussors, a hand tool with a heavy rigid head and a handle; used to deliver an impulsive force by striking.

The weapon's design is similar to the Hula instrument the 'Uli'uli a gourd with tiny seeds or pebbles within them utilized similarly to rattles.

She stills uses Martial Arts, and White Magic. She can summon waves of water, typhoons and sprout large flowers infused with white magic. She can also use Seasonal Gaze, where she can use her physical build to increase speed and stength.

Byleth also summons a Black Pegasus into battle.

### Noble Phantasm

#### **Divine Pulse; "Both Sides of Time are Revealed"**

Through the blessing of the Progenitor God Sothis, Byleth can temporarily reverse the flow of time and rewind to the very recent past, completely negating causal effects and damage. Only persons and creatures with clairvoyance-like abilities to see through time or who exist outside the domain of time will not have their consciousness affected by this high-level reversion. Byleth can use Divine Pulse a maximum of thirteen times, and it activates automatically if Byleth suffers a lethal blow and perishes. Turning back the hands of time by more than fifteen seconds is extremely difficult, and going back a full minute or further will generate resistance from the world. Uses of Divine Pulse can be recovered by resting.

#### **Overseas Memories**

With the use of the Crest of Summer Skill, Byleth can use her percussors to perform an elegant and beautiful dance as in to cast a spell, her Pegasus flies around her circling around with white magic her as she performs. Her dance imbues with magic to increase stats and skills and decreases the other opponents.

Her dance represents the memories of summer made in her time in at the tropical beach and experience of a relaxing summer.

## References

https://fireemblem.fandom.com/wiki/Byleth

https://hero.fandom.com/wiki/Byleth\_Eisner

https://vsbattles.fandom.com/wiki/Byleth\_Eisner

https://fireemblemwiki.org/wiki/Byleth

https://awakeningverse.fandom.com/wiki/Byleth\_Eisner

https://forums.spacebattles.com/threads/summon-a-servant-mark-vi-the-dark-six-f-sn-crossover-servants.370875/page-343#post-65953977

https://feheroes.fandom.com/wiki/Byleth:\_Fell\_Star%27s\_Duo