The only true trustworthy spoiler source for TROS is RedLetterMedia. According to them, we will get time travel and it will get Endgame treatment! For my speculation, Than… No, Palpatine wants to harvest all Skywalker lightsaber crystals, and once he has all of them… He will become the most powerful Chosen One in the galaxy! Meanwhile, Rey and the gang have to figure out how to beat Palpatine at his own game and collect these crystals before he does! Time is of the essence to prevent Palpatine from Snap! Crackling! And popping his… old joints. (it’s a long time ago in a galaxy far far far away, so I don’t think they invented infinity gauntlets)
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Or I’ll just wait for a more solid trailer to come out.
RedLetterMedia is also very well known for trolling with their fans, but not in a dirty way, more of a humorous way.