That needs to be an actual Keyblade in Kingdom Hearts 3.

I admit, I'll be very surprised if there's no Marvel or Star Wars content in Kingdom Hearts 3. At the very least there has to be some Pixar representation in there somewhere (Woody and Buzz summons were discovered in the files for KH2, but the models were unfinished since they lacked proper textures). At most, an entire Marvel or Star Wars world would be awesome (for Marvel I'd expect The Avengers since that'd be a good way to include multiple Marvel heroes at once, and for Star Wars a world based off of Episode VII could happen since I think KH3 won't be out until 2016, and they did do a Tron legacy level for KH3D since it came out like only a year and a half after the movie), but at the very least something like themed keyblades or summons would be cool too.