The XIII Event (XIII機関イベント XIII Kikan Ibento?, lit. "Organization XIII Event") is a recurring Event in Kingdom Hearts Unchained χ / Union χ. It starts on the 13th of each month, and grants players a Medal and Avatar Parts based on one Organization XIII member.

XIII Event - Number 1

 
 

XIII Event - Number 1 focuses on Xemnas and was available from January 13 to 19, 2017 in both versions. Players could obtain the Xemnas B Medal and Xemnas Style Hairstyle by completing objectives.

Each Event Quest contained a powerful boss, referencing Xemnas's position as boss of Organization XIII.

XIII Event - Number 2

 
 

XIII Event - Number 2 focuses on Xigbar and was available from February 13 to 19, 2017 in both versions. Players could obtain the Xigbar B Medal and Xigbar Style Hairstyle by completing objectives.

The Event Quests were filled with warp portals, referencing Xigbar's ability to teleport due to his control of space. The Armored Archer is a recurring enemy in the Event Quests, referencing Xigbar's use of a ranged weapon.

XIII Event - Number 3

 
 

XIII Event - Number 3 focuses on Xaldin and was available from March 13 to 19, 2017 in both versions. Players could obtain the Xaldin B Medal and Xaldin Style Hairstyle by completing objectives.

The majority of the Event Quests take place in Beast's Castle, in the area known as the "Bridge" in Kingdom Hearts II, where Xaldin was fought. These quests contain the target enemy, surrounded by six other Heartless, referencing Xaldin wielding his six lances.

XIII Event - Number 4

 
 

XIII Event - Number 4 focuses on Vexen and was available from April 13 to 19, 2017 in both versions. Players could obtain the Vexen B Medal and Vexen Style Hairstyle by completing objectives.

All of the Event Quests take place in either the Frozen Forest or Entrance, with a snowstorm going on, referencing Vexen's control of ice. Further referencing this is the fact that all quests contain Icy Crystal materials. The Defender and Armed Warrior are recurring enemies in the quests, referencing Vexen's use of a shield as weapon. Some quests contain Neoshadows with little HP, possibly referencing Vexen's ability to create Clone Sora's in his Absent Silhouette battle in Kingdom Hearts II Final Mix.

XIII Event - Number 5

 
 

XIII Event - Number 5 focuses on Lexaeus and was available from May 13 to 19, 2017 in both versions. Players could obtain the Lexaeus B Medal and Lexaeus Style Hairstyle by completing objectives.

All of the Event quests contain Power-based enemies, referencing Lexeaus's strength and fighting style.

XIII Event - Number 6

 
 

XIII Event - Number 6 focuses on Zexion and was available from June 13 to 19, 2017 in both versions. Players could obtain the Zexion B Medal and Zexion Style Hairstyle by completing objectives.

All Event Quests contain one or more Barrier Masters, referencing Zexion's use of a Lexicon as weapon. Some quests have fake Heartless, which can be passed through, and all quests summon a Trickmaster as Raid Boss, referencing Zexion's control of illusion.

XIII Event - Number 7

 
 

XIII Event - Number 7 focuses on Saïx and was available from July 13 to 19, 2017 in the Japanese version, and July 13 to 24, 2017 in the English version. Players could obtain the Saïx B Medal and Saïx Style Hairstyle by completing objectives.

All Event Quests take place during night-time, referencing Saïx's control of moon. Additionally, all quests have a Werewolf as the target, which has a counter above its head, and when it reaches 0, it will grow and attack with a powerful combo, referencing both Saïx's control of moon, as his Berserk ability.

XIII Event - Number 11

 
 

XIII Event - Number 11 focuses on Marluxia and was available from November 13 to 20, 2016 in the English version, and November 13 to 19, 2016 in the Japanese version. Players could obtain the Marluxia B Medal and Marluxia Style Hairstyle by completing objectives.

The Event Quests were filled with flower-like Heartless, referencing Marluxia's control of the Flower element, and the target for each quest was a Wandering Spook, which had a counter over his head, indicating the amount of hits the player could deal before it would use a devastating attack, referencing the fight with Marluxia's Absent Silhouette in Kingdom Hearts II Final Mix.

XIII Event - Number 12

 
 

XIII Event - Number 12 focuses on Larxene and was available from December 13 to 19, 2016 in both the English version and the Japanese version. Players could obtain the Larxene B Medal and Larxene Style Hairstyle by completing objectives.

The quests were filled with either fast moving enemies, referencing Larxene's lightning-fast speed, enemies with little HP, possibly referencing Larxene's ability to split herself into clones in her Absent Silhouette fight in Kingdom Hearts II Final Mix, or enemies that attack with lightning, referencing Larxene's control of the Lightning element.