She was "Playable Saber" from her Fate/Extra days, before Fate/Grand Order, when there were a lot fewer Sabers and a lot fewer characters with Saberface. She's colloquially "Red Saber." She's the Heroic Spirit Nero Claudius Caesar Augustus Germanicus, and she's representing the new action game Fate/Extella in its crossover with smartphone RPG Logres of Swords and Sorcery. 

This is of course a great opportunity to hear singer/voice actress Sakura Tange (best known as the voice of Cardcaptor Sakura) as the busty emperor/artist.

『Fate/EXTELLA』×『ログレス』コラボを本日より開始！ネロたちと協力して、陣営戦争の真っ只中にある霊子虚構世界（SE．RA．PH）から脱出せよ！ #FateEXTELLA #スマホログレス pic.twitter.com/o04U7O8Qh6

— 剣と魔法のログレス いにしえの女神公式 (@sp_logres) December 7, 2016

via _yamkon_

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Scott Green is editor and reporter for anime and manga at geek entertainment site Ain't It Cool News. Follow him on Twitter at @aicnanime.