Now that Santa Alter is back at the North Pole, mobile game Fate/Grand Order has introduced Chapter 4「Death World in the City of Demonic Fog - London」, British Empire during the Industrial Revolution. New Servants with the London gacha (draw rate boost runs through January 13) include「5★ (SSR) Mordred」, 「4★ (SR) Frankenstein」, 「3★ (R) Henry Jekyll & Hyde」, 「3★ (R) Paracelsus von Hohenheim」, and 「3★ (R) Charles Babbage.
An animated commercial featuring servants from this event, and the earlier Christmas, has also gone online on game site http://www.fate-go.jp/
Saber, 5★ Mordred, previously Saber of "Red" in Fate/Apocrypha (not to be confused with Fate/Extra's "Red" Saber). voiced by Miyuki Sawashiro (Houko Kuwashima in the old Deen F/sn), illustrated by Ototsugu Konoe.
Read her background, because it's kind of amazing.
Berserker, 4★ Frankenstein, previously featured in Fate/Apocrypha, designed by Meteo Hoshizora and illustrated by Takeshi Okazaki
Assassin, 3★ Henry Jekyll & Hyde - previously in Fate/Prototype: Fragments and a Berserker in Fate/Prototype: Fragments of Blue and Silver. voiced by Mamoru Miyano. designed by Nakahara
Caster, 3★ Paracelsus von Hohenheim- previously featured in Fate/Prototype: Fragments of Blue and Silver. illustrated by Nakahara.
Caster, 3★ Charles Babbage, new for Fate/Grand Order - designed by I-IV
4★ Lancer Artoria Pendragon (Alter) Ayako Kawasumi, designed by Akira Ishida
★5 Archer Nikola Tesla designed by Namaniku ATK
★5 Caster Solomon - antagonist, designed by Takashi Takeuchi
500 Years Dedication - art by Azusa
Necromancy - art by Konoe Ototsugu
Awakened Will - art by Kinuta Kouji
Three new Mystic Codes were also added for the game's player protagonist masters
Mage's Association Uniform
Atlas Academy Uniform
Chaldea Battle Suit