Meltryllis

Meltlilith (メルトリリス) is a character resembling Sakura Matou and BB in Fate/Extra CCC. She has giant, pointed needles for feet, a penchant for fighting, and an uncanny amount of fighting ability. Her face resembling that of BB is also a trait shared by Passionlip.

Abilities
A scene on the second trailer confirms that she's a lower body combatant that use the pointed needles at the edge of her leg armor.