Sion Eltnam Atlasia
That's her full name, she's a character from Melty Blood (same developer, after all). Dunno why it's a u instead of an a, nor why they're going with that name instead of Sion or her full name, but she looks to be the same character.
This game looks sick. It's how beautiful the 3d backgrounds are that got me. As for characters, I like the look of Vatista and Linne looks pretty strong too, but Seth is the one I have the most hype for. His mid-air flip slash looks strong, and his mid-air stall into a dashing grab can be great...
If you're used to playing Xianghua, I'd suggest Leixia. Her style is similar to Xianghua's.
I could be wrong, as I haven't looked into it, but it seems like Xiba is faster than Kilik with decent mix-ups.
Otherwise, other suggestions would be Natsu or Viola.