An article by Hokanko-alt blog has provided a summary on the Kingdom Hearts content for the Dengeki PlayStation 600th issue that will be released tomorrow. Tetsuya Nomura, director of the Kingdom Hearts series, has provided some details on the story for Kingdom Hearts χ Back Cover and explains some details that will be brought to the story of Kingdom Hearts III.
Throughout the story in Kingdom Hearts χ Back Cover, details on the "Lost Master" will be revealed and then continue in Kingdom Hearts III. Master Xehanort's Keyblade will be introduced in Kingdom Hearts χ[chi], which then ties to Kingdom Hearts III. Aside from all that, the traitor originally mentioned in Kingdom Hearts χ[chi] will finally be revealed in Kingdom Hearts χ Back Cover.
Translations of the interview summary can be read below thanks to @_ikenie & Kayla Copeland (firstname.lastname@example.org).
Mini-interview with Nomura in Dengeki. Unchained talks about the Lost Master, further expanded upon in KH3. The setting of Xehanort's keyblade is discussed in Unchained and is connected to KH3. 7 Lights and 13 Darkness - other than that revealed in KH3D, these will be hidden until the very end of KH3's story. There is a link between 0.2 BbS and KH1-2's stories. Narrator of χBC is Chirithy. KHuχ: Chirithy is the player's guide. Master of Masters is the teacher of the 6 Disciples. The traitor will be revealed in KHχ Back Cover.
--About the cover:
Tetsuya Nomura's comments in this issue:
-There is a congratulatory message regarding the overlap of issue #600 and the announcement of KH2.8.
-The king (presumably King Mickey) and the others were drawn beforehand for the sake of expediting the schedule, but now they're being recolored to create a sense of unity.
-They've depicted this on the front cover several times.
-He's going to talk about KH2.8 and KHIII
-The “Lost Master” is talked about even in [KHx], but it will be used in KHIII
-The creation of Xehanort's keyblade will be discussed in [KHx] and will tie into KHIII
-Kingdom Hearts will also be discussed further, more than the series has so far
-D23 (November 3rd) will feature a “theater” concept, so he's hoping we're looking forward to the video!
-The part of KH3D that explains the 7 lights and 13 darknesses will be carried on through the end of KHIII
-Since “Keyblade Master” is a special title, what's necessary to become one will be taught
-0.2BbS and KH1-2's stories will be linked together
-Chirithy is the one speaking in xBC
-Chirithy is the player's guide
-The “Master of Masters” is the teacher of the six apprentices, and it will be revealed in xBC who the traitor is