There are two new Extended Secret Ending screenshots shown in a magazine! Click to enlarge:

Extended Secret Ending: Old Man Using Magic Extended Secret Ending Battle

It appears that all five of the currently seen characters in the Extended Secret Ending can wield Keyblades, whether they have Keychains or not.

From the magazine, it’s said that the Enigmatic Soldier, being the strongest enemy in Final Mix to battle, is defeated easily by the Old Man in the Secret Ending. We see him defeat all three of the Armored Unknowns easily.

In the screenshot we saw from the Commercial, the mysterious man looking up at Blue Kingdom Hearts is apparently looking after one of the Armored Unknowns:

Someone Watching Blue Kingdom Hearts
Someone Watching Blue Kingdom Hearts