Have a look at the beginnings of Episode Gladiolus.
The four protagonists of the main game will each receive a story DLC over the course of 2017, and Square Enix starts taking care of these with Gladio in Episode Gladiolus, which will also feature Cor Leonis.
The action-oriented DLC will have new areas, new monsters, as well as new weapons that you can use in the base game as well. The final boss will likely be Gilgamesh. Gematsu reports that the DLC will take about two to three hours to complete, which doesn’t seem like a lot of time. However, it will likely be way longer if you try to explore everything during the new plot.
The Episode Gladiolus DLC will arrive on March 28 on PlayStation 4 and Xbox One, and it’s part of the 25 dollar/euro Season Pass. The second episode, Episode Prompto will arrive in June.