https://www.khinsider.com/news/KINGDOM-HEARTS-Dark-Road-launches-on-June-22nd-16984
There are two Trailers and both are intriguing.
First off: Dark Road’s Trailer implies Xehanort is the Player Character of Union Χ traveling to the Present Era.
This explains Ventus showing up as well as Lauriam and Subject X/Skuld(as indicated by the Axel Character File) showing up.
https://www.kh13.com/news/axels-story-i-will-not-forget-you-kingdom-hearts-character-files-translation-r3283/
Considering Larxene’s Character File calling Luxord a Con Artist…
https://www.khinsider.com/news/KH-Character-Files-Short-Stories-Xigbar-Marluxia-Larxene-16690
It seems likely considering Luxord appears in Shibuya as Yozora’s chauffer and has Brain’s Earring and his importance he is infact a Reaper and his having Brain’s Earring is due to him claiming it as Elrena’s fee for the Reaper’s Game which she and Demyx had won… Then he dumped them in Radiant Garden rather than where she was expecting.
Xehanort probably saw Luxord and Demyx popping up at the same time as Elrena and decided to rip out their Hearts first before Elrena made her getaway explaining why Larxene hates people in lab coats.
Xemnas obviously didn’t recognize Luxord since he never met him though he probably got a description of Brain’s Earring from Scala ad Caelum and when he recognized Marluxia when Xigbar brought him in thanks to restored memories from his experiments he saw a means to bring Brain back.
Luxord of course decided to make sure he got killed by Sora first derailing Xehanort’s plan utterly.
Now for the other Trailer: https://www.youtube.com/watch?v=L6_PF9DUP6E&feature=emb_title
The final part of the Trailer implies that Kairi will start in the Final World with Riku then go up alone against the Master of Masters(who shares a Voice with Noctis).
Considering Kairi has Noctis’s fighting style I suspect that the Master of Masters removing his hood will reveal Noctis then Kairi will beat him causing him to be revealed as Noctis’s Nobody and he will unleash a “taking you with me!” attack before fading sending Kairi to Shibuya where she’ll encounter Yozora.
I suspect that Yozora having his or should I say her Heart(most certainly the Mysterious Star) replaced with another’s has the Master of Master’s Heartless and Yozora will remove it upon learning that Nobodies can grow Hearts upon which it will dive into Kairi and lose causing the Master of Masters to be recompleted in his true identity.
As for whom the Master of Master’s true identity is… Considering the Cat theme and personality I suspect Pete’s future self though how Pete would get into Noctis is beyond me though probably ties into Riku not being present when Kairi is fighting the Master of Masters.