Main heroine of Melty Blood.
Born Sion Eltnam Sokaris (シオン・エルトナム・ソカリス).
If she loses herself, she will turn into a vampire (Sion Tatari).There is also a possibility she will turn into the Dust of Osiris in the far future.
Sion also makes a guest appearance in Under Night In-Birth (named Eltnum).
The following tags implicate this tag: eltnum (learn more).