Anyways: Each character has their own story arc except WW who he felt was forced into it.
This seems odd, because we've already seen from the trailers that the Amazons and their mother box are significant both in terms of the prologue history of Darkseid's contact with Earth before and because Zack Snyder has spoken to Diana's arc in interviews, saying that her arc in Justice League is about showing how Diana has "fully evolved into someone whos embraced mankind, partly through Supermans sacrifice." She mentions the Age of Heroes in the trailer, which is likely a reference to the past she knows from Themyscira's history, and we see her in the trailer helping Bruce recruit the League. Taken together, that hardly seems like she has no arc and is out of place in the narrative.
Aquaman's arc is about returning his motherbox to Atlantis,
This is neither here nor there, but I'm curious about this notion of "returning" the mother box, as if Atlantis is where it was meant to be all along. Plus, it seems fairly obvious that returning an item to a location isn't a character arc. From what we've seen, having Arthur embrace his role as a hero and want to work with others is a part of his character development.
Cyborg's arc is about his connection to a motherbox,
Again, that seems oversimplified and something anyone could know from trailers and such already. It's also weird not to mention anything about Silas Stone's kidnapping.
Flash's arc is about the speed force(He said they explain it perfectly),
I'm not sure how this is an arc or why the speed force would need to play such a significant role. It also fails to mentiont things like Barry's father being in jail, Iris, or what seems to be Barry's lack of friends and how the league would give him that family and friends that he's been missing. Plus, there's Barry's unique dynamic with Batman that Ezra Miller has described as "a relationship between someone who is naïve and excited, and someone is experienced and jaded. Barry and Bruce get a kick out of each other because theyre seeing sort of themselves, but reflected in this very warped mirror. I think they have a lot to learn from each other."
Batman's arc is about forming the league
Sure, but that's obvious from Batman v Superman and trailers. It's also limited given that the other layer of Batman's arc is teased in the trailer and in the movie's official description: he is learning how to play well with others again and to reform for having lost his way.
Superman's arc is about the codex in his blood.
Given everything else going on with Superman, reducing his arc to something so minor and physical seems a bit odd. Nonetheless, Man of Steel already delved into the codex in a fairly significant way both by establishing that he is the codex and by showing Clark choose to relinquish its ability, or his blood's ability, to be used to generate new Kryptonians using the Genesis chambers on the Kryptonian ships in a fulfillment of Zod's wishes. The only way the codex would be significant here is if it was part of what made it possible to resurrect Superman. That hardly sounds like a character arc, though.
Aquaman lives in a lighthouse, he refuses to be the king of atlantis.
I see, then, so Arthur would have more of an arc than just returning a mother box. Still, this isn't exactly something that one couldn't guess from the trailers.
Flash is only able to time travel 3 minutes into the past. In the end Bruce gives him a new armored suit that will help him to go farther.
This confuses me. Presumably, Bruce would want to help Barry travel farther through time because he knows that Barry does it and has to do it in order to warn him about the future. However, that means he already knows that Superman could be evil (and alive!) and that Lois is the key. If he already knew about Superman being alive and evil, then shouldn't his first priority be to guard Clark's body? It also suggests that the movie spends a substantial amount of time just building up to the point we already got to in the Knightmare sequence and the Flash warning, making it so we'd have to watch yet another sequence of events where the heroes try to do something different. But do they? If the armored suit is to match up with BvS, then Barry doesn't do anything differently. How can it be possible for things to ever fix themselves or go in the right direction, if the same mistakes are repeated? Why would viewers be forced to watch basically two versions of the same timeline in the same movie? Would they even, or would things sort of just change around Barry? I was always under the impression that Barry's warning in BvS was the extent of the time travel, and that Justice League wasn't about showing what led up to that, but how things were going to be different now that Barry did warn Bruce.
WW returns to Themyscira after a century because she will die if she doesn't, amazons are only immortal if they remain on Themyscira. We see her mother Hippolyta.
This is okay, but I have a hard time believing that this is the most important or memorable thing about Wonder Woman from the movie. It's also not really a canon thing, as far as I'm aware; I don't believe the immortality has ever been something that has to be recharged, so to speak. I also don't know whether we're supposed to assume that after returning, she can leave again for another hundred years or not, because if not, this spoiler implies that Wonder Woman's presence in the DCEU would be over after Justice League. That doesn't seem to align with Patty Jenkins' recent comments that she'd like to set a potential Wonder Woman sequel in modern day America. I also don't know why, if this was a concern, Diana wouldn't have returned in the many years prior when she had the time to do so.
Superman has about 30mins of screen time. He's bad for at least 15mins of it. Steppenwolf convinced him that during the battle of Doomsday(He doesn't actually call him that) Lois was killed, Batman had a chance to save her but he saved himself. Steppenwolf says ''He killed your world, now kill his''. There's a little short fight between Batman & Superman, Superman wins and is about to kill Batman when Lois arrives(Flash). That's all he told me for now, sorry I couldn't get him to answer all the questions. He said he might answer them soon.
This spoiler implies that Superman is revived, but with amnesia. It's not clear why he would just believe what some scary stranger tells him or why he would suddenly abandon his previous mindset about Earth being his world to wanting to destroy it just to get back at Batman. It's also unclear why, if Flash has gone back in time to let Bruce know about Lois being the key, why Bruce wouldn't make sure to be prepared for an evil Superman attack with kryptonite and to be very clear with Clark that Lois is alive. It's also unclear why Batman would be facing Superman alone instead of with the league's support. Finally, I'm trying to reconcile this spoiler with the previously provided one. The original spoiler say Superman wears the black suit with longer hair while the Knightmare sequence showed neither. Also, the spoiler also said that Steppenwolf kills the Justice League and then Barry goes back to the past to prevent it. So, presumably, this version of the timeline -- the one in which Lois arrives to stop Superman -- is the second or new and improved timeline?
In short, I feel like too much of this spoiler depends on stuff we already know from trailers, etc. and from BvS. The time travel in particular seems like an unnecessary headache, included in the spoiler because it was available for inspiration rather than from actually seeing the movie.