Remilia Scarlet

A designer baby created by Remus Scarlet using Constantine Song's and his own genes. She is Lucius Scarlet's brother, who, just like with him, Excellion requested be given vampiric traits. Though she isn't a true vampire and neither is her brother, they just share similarities, thus, pseudo-vampires.

She was involved in one of the eldritch incidents caused by Lucisfear and the Jester, having fought Fynn and Lucius at near full power. She was knocked unconscious by the duo and her sanity was brought back by force feeding her Lucius's blood.

Appearance
She had two main forms based on her current elemental affinity:

Her "default" or birth one, with golden hair and eyes, pale skin and functional vampire fangs.

And her darkness-attuned form, purple hair, red eyes, still extremely pale and retaining all her vampiric traits.

Courtesy of Constantine's genes, she has access to a pair of wings, which also automatically activate in dark mode. These don't allow actual flight unless her body's given far into darkness due to her weight, but they do allow for gliding and dashing.

After being influenced by a fictional eldritch god and fully corrupted, she no longer has access to her default status and she is permanently in a state of nearly full corruption.

Personality
Her personality basically consists of stroking her own ego and acting like she's extremely experienced despite being literally four.

Successor of the dark
After being fully corrupted, she's become able to properly utilize the element of primordial darkness as established by the elemental she derives her powers from.

Pseudo-vampirism

 * Her body is being destroyed constantly due to her forced elemental affinity to darkness, she needs to obtain someone else's blood to mitigate the effects and attain a momentary balance. Though Lucius's blood is really effective at this, she doesn't really care whose blood it is.
 * Like Lucius, she has superstrength, speed, stamina and durability. Though in her case she is faster and stronger than him, but less durable.
 * Enhanced senses
 * Drinking blood also replenishes her strength.

Trivia

 * The only reason Remus's surname is Scarlet was so Excellion could use both the name and design from Touhou 6.
 * Her and her brother's abilities are direct references to two of Excellion's old OCs who became magic elements and joined Excellion.