Marvelous has hinted at DLC content so we can guess that they will include more characters in it via DLC. But, who?
- For Servants from Fate/Extra (and CCC) that aren't currently playable, we have Robin Hood, Francis Drake, Nursery Rhyme, Hans Christian Andersen, and Arcueid Brunestud.
- Robin Hood is actually mentioned in the Fate/extella extra materials book that comes with the Noble Phantasm Edition. He's a member of Tamamo's faction.... as the court jester whom Tamamo shocks a lot.
- From other Fate media, we have breakout characters like Scáthach, Arjuna, Dantes, and Jeanne Alter from Grand Order, Astolfo and Semiramis from Fate/Apocrypha, Ozymandias, and Byrnhild from Fate/Prototype.
- Romulus is mentioned in the Fate/extella extra materials book that comes with the Noble Phantasm Edition, and is stated to be a Top Servant in the Moon Cell. So its possible. Jeanne Alter is more likely to be a DLC costume.
- Astolfo's chance might go up considering the sequel will feature his boss, Charlemagne. However, it may render him similar to Altria since that's what happened to her since Gawain was the Arthurian Myth representative in Extella.
- All of the DLC revealed at this point however is outfits for the Servants, so unless Marvelous is keeping the Servant DLCs under some tight wraps, jossed?
Gilgamesh was apparently ordered by someone to find the Regalia and neither of those two seem likely to have joined Altera's faction with the intent to destroy civilization, so guessing there's some kind of hidden motivation for them to be in her faction.
- Jossed, Gil's true motive is to prevent "body Hakuno" killing himself and stopping Archimedes' plans from succeeding.
In Fate/Grand Order's London chapter, Andersen found out the true purpose of the system: summon humanity's best heroes to fight against threats which endangers humanity's existence as a whole... like alien invasions of the Velber. It's also possible Solomon knew about Velber's existence and their invasion of Earth in the future, which is why he became mad and decided to destroy humanity before Velber comes.
- It's been revealed in Grand Order that Solomon burned the world for completely different reasons, so that bit's jossed. Still possible that the true purpose of the Heroic Spirit summoning system applies for fighting Velber.
It's mentioned that Altera's sword was taken from a Divine Spirit who was using it to defend the Earth, now call me paranoid, but isn't mentioned that Altera has always felt a connection to Mars the Roman God of War?
- Well.... Said Divine Spirit was Ares/Mars' predecessor, as revealed in Altera's route.