Ok, since like Is aid, I’ve cooked a little too long. So, I had to split it into parts
Part 1: Beginning of the end
Overall, the plot line is mostly the same as canon, except the MC has been feeling very uneasy around Kieran and feels that something’s off. Not just appearance, but something, really, REALLY wrong. The MC has also been plagued by nightmares, and all of them have a Kieran that looks corrupted and have chains, and keep sending death threats. However, it was all just a nightmare. Fast forward to the crater, everything is the same, and that feeling disappears, Kieran shows no sign of being corrupted. Skip to the epilogue, basically the same but no Pecharunt involved. But MC feels that something is watching them, and even when she’s alone or a group, she feels being watched. On the last day of the trip, when he/she woke up, there was a letter, saying that he will come and end him, the ink was in purple and there was a series of random numbers. It was eerie but no information can be found.
3 months later, MC got a call from Carmine to come back to BB academy to act as a mentor for new students, since, he/she became champion before. MC agreed but the Zero Crew decided to tag along. After a while, when MC checked his/her boxes, he/she realized that Terapagos is missing. They went to Carmine a who was with Briar, and told them that Terapagos is missing. They were shocked before Carmine revealed that strange things were going on in the academy. Power outages, wild pokemon being more aggressive, students complaining of nightmares and so on. Briar is trying to find out what is going on as they are becoming more frequent. When MC returned to the Terrarium (battling some aggressive pokemon), was the Terrarium Core slightly more purple than usual? Anyways, he/she saw Kieran and Kieran asked for a friendly match, right here in the Terrarium, that uneasy feeling as back but couldn’t put a finger on it, in the end, he/she didn’t have a choice, a friendly battle commences.
Oooooooh I love this idea so far!
My only question is how would the epilouge play out without Pecharunt? (Unless you're talking about something else.)
Also gotta love how Kieran is like "sure let's have a friendly match here while the Pokémon are acting aggressive surely nothing bad can happen!"
Unless he (Or Pecharunt/Dokutaro is behind it, which could be the case here)
Can't wait to see the next part! :D