Fate/EXTELLA LINK

Above the ruined earth lies the realm of SE.RA.PH, a virtual world inside a lunar supercomputer. In this last refuge for humanity, powerful Servants — sentient, digital recreations of famous figures from Earth’s lore and history — battle rogue programs (and each other) to establish dominance and enforce their kind of peace. But peace may never come again, now that a new threat has arrived to wage apocalyptic war. Standing against the destruction is the hero Charlemagne, a dashing young knight with a hint of sadness behind his bright smile. Join Charlemagne and his comrades — the bumbling paladin Astolfo, the flamboyant Emperor Nero, the mischievous fox spirit Tamamo no Mae, the cynical rogue Robin Hood, and many others — as they rush across the battlefield in the name of humanity.

With the sudden appearance of Karl de Grosse, who possesses the power of the Oracle that can enslave and assimilate all things, the Moon World was about to get dragged into a new war. The Master, Charlemagne, and the other Servants confront the invasion on the principle of the assimilation of all beings. However, those that agree with Karl de Grosse, those that are lending support for not only their own benefit, and even former allies assimilated and stand before Nero and the others as an enemy by the power the Oracle. Furthermore, a young Altera that had gone missing can be seen beside of Karl der Grosse… As various expectations intertwine, a new war is about to begin!