"World of Final Fantasy" has just launched for the PlayStation 4 and PS Vita, and the game boasts several returning characters from multiple "Final Fantasy" games. The cast of summon characters is about to get bigger as Sora, the lead character from the "Kingdom Hearts" franchise, is coming as free DLC this December.

Announced via Twitter, the DLC is going to be available only for a limited time, so gamers should go online and acquire him as soon as he becomes available. Sora's inclusion in the game is part of the celebration for the upcoming launch of "Kingdom Hearts HD 2.8 Final Chapter Prologue," a spin-off title setting the events for "Kingdom Hearts III."

Sora's design will be based on the games included in "Final Chapter Prologue" instead of his wardrobe from "Kingdom Hearts" or "Kingdom Hearts II." Just like the other guest characters he is not going to be modeled as an inter-dimensional traveler but as a different version of Sora, one that has always lived in the world of Grymoire, and he will have his own plot and side-quests.

Polygon points out that Sora is going to be the first non-"Final Fantasy" lead character that is added to the game. He will be joining the ranks of The Warrior of Light and Princess Sarah from "Final Fantasy," Bartz Klauser from "Final Fantasy V," Cloud Strife and Tifa Lockhart from "Final Fantasy VII," Vivi from "Final Fantasy IX," and Tidus from "Final Fantasy X."

The report also points out that Sora is a perfect fit for the game given that the "Kingdom Hearts" series is built primarily on the concept of cross-overs. For those unfamiliar, "Kingdom Hearts" and its sequels and spin-offs mix the characters of the "Final Fantasy" games with Disney worlds and characters such as Simba from "The Lion King" or Ariel from "The Little Mermaid."