Final Fantasy XV is now a year old, and to celebrate Square Enix has held a special Active Time Report stream on its Japanese YouTube channel to reveal details of updates that are still to come to the game, including a new character hot-swapping feature.
During the stream (helpfully briefly summarised & translated via Reddit) a video revealed that you'll soon be able to take control of Noctis, Prompto, Ignis or Gladious during battles, whereas formerly the other three characters would be mostly controlled via AI with you issuing commands as Noctis. You can see the clip in the video below at 1:26:10 in:
According to the translation, you'll be able to do this hotswapping throughout the game, meaning you'll be able to complete almost the entire game as say, Ignis or Prompto if you want to apart from the sections were certain characters leave the party in the story.
According to a thread on ResetEra, there's due to be an English language stream later tonight to reveal these features in English, so if there's anything else major to add expect more updates tomorrow.