Master Ava's role in the Master of Masters grand scheme has nearly finished. She gathered a legion of Keyblade wielders to survive the end of the world in the form of her Dandelions, and she even accomplished a lesser-known facet of her task, one known only to her and those involved. The Master selected five new Keyblade Masters to separate Ava's Dandelions into Unions and lead them in the Foretellers' stead. All of these Masters know their role thanks to Ava, but they don't know each other. However, now that the Keyblade War has come and gone, it's time for them to meet, and they're to do so at the Keyblade Graveyard.
This is a recap and interpretation of the major events in Kingdom Hearts Union Cross quests 661 through 675. These mark the first official major storyline quests to come out of the Union Cross subtitle. Until this point, the game was branded as Unchained X and only served to retell the original Kingdom Hearts X story for international audiences. Once Unchained X caught up to and passed X's final chapter — the Keyblade War — it took the name Kingdom Hearts Union Cross to symbolize that all the stories told from this point on would consist of never-before-seen content, which includes this first meeting between the new Union leaders.
The First Four Leaders
Ven
Ephemer is the first to arrive on the once-battlefield, and to his surprise, Skuld is the second. It's not that he's surprised she's a Union leader; rather, he's surprised that Master Ava wasn't lying to him about there being others to help him with the Dandelions. He was worried he'd be alone in it, so Skuld's presence is reassuring. It doesn't take long for the third wielder to arrive, but unlike Skuld, Ephemer doesn't know him. However, longtime Kingdom Hearts players certainly will.
The man introduces himself as Ventus — Ven for short — and it's clear he's a ball of nerves and self-doubt. He's envious of the fact that Skuld and Ephemer not only already know each other, but they're friends. He's been on his own for as long he can remember. He also can't figure out why Ava would choose him to be a leader, as he's not good at anything, nor did he really know her that well. It relieves him, then, when Ephemer and Skuld both assure him that Ava must have had her reasons and that he's a part of their inner circle now, so he won't have to be alone anymore.
Brain
The fourth wielder likes the sounds of the conversation he's overhearing. He introduces himself as Brain, and after some small talk, he reveals himself to be a curious and calculating individual. He first learns that Ephemer isn't the team's overall leader like he figured him to be and that Skuld sees the rulebook given to them by Master Ava as something set in stone rather than a set of guidelines. Once he's made Ava the topic of discussion, he asks the group its opinion on whether they can trust her. She is, after all, forcing them to lie to everyone about the Keyblade War.
Ven and Skuld are both on the fence about the idea, but Ephemer already knows where he stands on it. With more authority than he probably means to, he tells the group that they'll follow the rules, as he doesn't want anyone having to carry around the burden of the war's events. To Ephemer's embarrassment, Brain happily falls in line with this. He was sure from the moment he saw Ephemer that he would be a good leader. He believes he'll lead them down the right path, and his confidence encourages Ven and Skuld to throw their support behind the idea too. Still, Ephemer wants to wait till the last wielder shows up. There's only one left.
Ephemer's Reason
Ephemer's decision regarding the Keybalde War comes from two particular memories, which he recalled before answering Brain's question. The first is of his meeting with Master Ava about the situation. They had just finished discussing the end of the world along with his becoming a Keyblade Master and Union leader. Here, Ava handed him the rulebook and told him that one of the rules he and the others had to follow involved keeping the Keyblade War a secret, something the Chirithy had the power to do.
Ava wanted the world that the Dandelions would be living in to be something like an alternate reality that lacked the "doom and gloom," and Ephemer disagreed. The past makes the future, so he thought people should remember the war, even if it's painful. However, Ava said something that made him second guess this belief. She wondered if he would feel the same if he actually fought in the war — witnessed it. After this, he experienced the second memory, finding the protagonist lying half-dead in the middle of the Keyblade Graveyard. That was all he needed to see to get on board with Ava's point-of-view.
Tragic Memories
Speaking of Kingdom Hearts Union Cross's protagonist, things are going well for them. Life is simple — normal. They even joined their first Party with a group of acquaintances they met back in quests 635 - 645. There is one thing bothering them, though. They've been having these really strange dreams lately, recurring nightmares that see them living out a specific set of miserable events. The weird thing is, these dreams play out as memories, but as far as the protagonist is concerned, they've never lived through anything like them before.
Tonight they had a particular one about lying in the mud while surrounded by broken Keyblades and vanishing hearts. Then they battled Master Aced in Foutain Park. He lashed out at them after the three of them, Skuld included, disagreed about what constitutes justice. They woke up after the fight to Chirithy, who claimed they were having a nightmare. Felt real enough, though. Regardless, they agreed with Chirithy to take the whole day off and get some rest.
Kingdom Hearts Union Cross is on Android and IOS.