Archetype-EMIYA almost 6 years ago Debatable whether that is Assassin of Black. It looks a lot more like the Stray Servant that was discarded from FS/n before it was released. Said servant was also a servant of the shield as opposed to Saber being a servant of the sword.
Terashi88 over 5 years ago Trailer was recently announced for Fate/Grand Order. The shield girl appears to be a character in the new game.