<p>I would say you should do these things before playing Fate/Extella: watch some YouTube videos of Fate/Extra Servant dialogue, and read at least a bit of Fate/Extra CCC "game progress log Gilgamesh" (literally google that quotation). Unfortunately there's no Fate/Extra CCC game translation; if you have a PSP, you can probably buy Fate/Extra online cheaply if you're that interested in it. Fate/Extella follows Fate/Extra and then seemingly F/E CCC, but it's like F/Hollow Ataraxia in that it has its own new route of F/Stay Night rather than following a traditional route. I will say this so you don't get confused even though it's SPOILERS: Nero was the main Servant from F/Extra, Tamamo joined Nero&Hakuno in a diverging plotline from F/Extra, and Gilgamesh seems to have been the F/E CCC Servant. Hakuno for reasons I'm unsure of because of lacking F/E CCC translations doesn't remember Far Side of the Moon events; in F/E CCC she doesn't recognize Gilgamesh on the Near Side of the Moon during the Holy Grail War until she sees him again as her Servant in her My Room; in F/Extella, Hakuno just doesn't remember Gilgamesh period, while Gilgamesh does remember Hakuno. Hakuno Gilgamesh is sorta important to the White Saber route, and his actions/words don't fully make sense without knowing there is a F/E CCC context.
</p><p>SPOILERS in case you haven't watched the F/Z or F/SN anime (you probably have): Quite a few Servants are from either anime: Iskander, Gilgamesh, Saber, Red Archer (Kinda), Cu Chulainn, Medusa. Most of the rest are from F/E or F/E CCC: Nero, Tamamo, Red Archer (Kinda), Gawain, Li Shuwen, Karna, Lu Bu, Elizabeth. On the other hand, Ruler is from Fate/Apocrophya. Scholar Caster is the only entirely new character. White Saber is sorta new, she first appeared in F/Grand Order but this is her first true main role. The more you know about F/E and F/E CCC, the more you'll probably understand their identites. But it's not super critical probably. Just go read Nero and Tamamo wiki pages at the very least, since they're two of the three main Servant heroines.
</p><p>Also, Blue Saber (from F/Z and F/SN) is only unlockable by in-game actions unlike plot progress for the rest. Unlockable means their side-story and free battle. I don't believe the timezone part is applicable anymore in the English version, since it seems to have been a Japanese culture tidbit that even the Japanese didn't think of to use. Just YouTube how to unlock her.
</p><p>BTW: I saw a YouTube video saying F/Extella is coming out on the Nintendo Switch. If you have a Switch and rather get it on the Switch, it might be better to research more about that. I really don't know much about that situation.
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