@shiningsight / plotted starter.
Uxie was furious.
They had always been, for the most part, completely apathetic to whatever their siblings did in their free time. As long as they did their duties and didn't pick fights, Uxie didn't care. In fact, Uxie liked to believe that they barely even felt emotions- though logically they knew that this was not the case, and that they simply repressed their own emotions because they weren't valuable in the performance of their duties or the pursuit of knowledge. In fact, emotions could very much hinder both of those things. As proven by Palkia fleeing the universe itself due to their desparation and their (justified) hatred towards Arceus, neglecting, or rather, abandoning their duties.
No, Palkia didn't let space here collapse, obviously. They were too smart to let that happen, because it meant that Arceus would come after them and berate them, perhaps even punish them, for neglecting their duties. In Uxie's humble opinion, however, fleeing the universe to go play different roles in other worlds was abandonment. Uxie denied to themself that it was more than the duties. Uxie denied to themself that they felt as if Palkia had abandoned their siblings as well. But deep down, that was how they felt.
Then Palkia had the audacity, the absolute audacity, to just show up for Mewmas as if they hadn't been absent for the last five to occur. As if they hadn't skipped one of the few opportunities all of Arceus' children had to get together without the creator, and then shown up this year as if nothing was wrong. They had gone checking with their siblings about the gathering, just to confirm when it was happening. Upon hearing this from Azelf an hour before, Uxie had taken on their human form, since Palkia seemed to be so fond of that now, and waited outside Acuity Cavern with an uncharacteristic scowl on their face.
They studied the clouds, waiting to see a flicker of otherworldly white amongst the rather miserable gray clouds. It was a several hour wait, and the sun had set, leaving the stars twinkling in the sky. Which would make it a bit more difficult to spot Palkia depending on how high they flew, given Palkia's bright coloring and the way they seemed to constantly glow. They would blend in with the stars. However, not long after this thought occured to them, they spotted a shooting star that seemed to be rocketing towards the lake.
Showtime, they thought with a snort.
Uxie stood up and crossed their arms as their older sibling got closer and closer. They wanted to make it obvious that they were not happy, and that Palkia would have to beg for their forgiveness. They glared at Palkia as their actual body shape manifested in their vision instead of them just being a large shooting star.
"Well, Palkia? What do you have to say for yourself? What could possibly warrant you abandoning your duties for five. whole. years? "