Can't Get Rid of Me That Easily

The Illness

Ages of the characters (yes believe me this will be important later in the story):

All the young trainers: 15
Bonnie and max: 10
Professor kukui and oak: 35
Professor sycamore and burnet: 33
Delia and lusamine: 34

Now the actual story

Ash and Pikachu have been in alola for the last few months after they lost the kalos league finals, and right now they're outside professor Kukui's house looking at the stars,

"Pika pi?" Pikachu asked knowing Ash didn't seem quite right,
most people wouldn't know what the yellow mouse is saying, but Ash knew exactly what it was saying, "I'm ok buddy no need to worry," Ash said to his partner with a smile. "Ash! Dinners ready!" professor Burnet yelled from inside the house, "coming!" Ash yelled back,

It was the next day, and he was at the pokemon school not feeling very well but went anyway on not wanting to worry his classmates, as professor Kukui was calling everyone's name out he went "Ash? " he got no reply,
"Ash?!" again no reply, it was unlike Ash to ignore Kukui,

Meanwhile in the kalos region, Greninja just sliced through the last of the red vines, "ja?" it asked "Ash?" then Z1 asked "Greninja what's wrong we just finished clearing out the vines surely you should be happy?" "It's Ash somethings not right with him. Huh!! It's his aura I have to go to him right this instant!!" Greninja yelled but it came out like this to humans, nin ninja ja greninja, "then let's go find Clement and Bonnie they will be able to find him!" Z2 exclaimed.

Back at the pokemon school, "Ash you're worrying me here, why aren't you answering?" the professor asked in a worried tone, Ash still didn't answer his face was just blank, petrified, everyone was worried at this point, Mallow rushed over to him, she quickly wrapped her arms around him and said "Ash are you ok?" close to tears. Ash then got up and told them "call Oak, quickly," he then collapsed onto the floor. Pikachu quickly went to his side and zapped him to try and wake him up but their was nothing absolutely nothing at this point Pikachu had tears streaming out of his eyes along with Mallow, Lillie, Lana and Kukui, even his friends pokemon were trying to wake him up.

Meanwhile at the alter of the sun the four tapu were talking among them selves, "something isn't right with Ash," Tapu Koko said worryingly, "hmm, we should go check on him," Tapu bulu replied, Tapu Lele and Tapu Fini agreed. The four island guardians rushed over to Melemele island.