>>33608350Tapu Koko enjoys fighting maybe a bit too much. We are told the battles are mostly in honor for the Tapus but the only actual festival with such a theme we see is the one in Melemele island which is where Tapu Koko lives. And even though he is reclusive he is still "in the audience" watching the battles.
The library mentions that the Tapus were once the generals of the armies of each island's king, but after seeing how much destruction their Z-moves would bring they decided to leave and not get involved in the wars of men. I kinda think Koko may have had some revelation there, not exactly "what have I done" but instead that the fights he was having were not fair since the only worthy opponents were the other Tapus. And that is also why he saves Nebby and (You) in the game's events, since he knows Nebby will evolve into Solgaleo/Lunala and sees in you a strong trainer, so he thinks he finally can have a worthy match.
As for Tapu Lele I haven't got too much on her, but judging by what we are told of her and how Olivia is (seeing that Kahunas mirror their Tapus a lot), Lele may be more concerned about the well-being of people than the other Tapus. We know she drops her scales that are able to heal anything, but is exactly that healing property that drives people and pokémon to fight over them, even though Lele drops them almost as if they were pennies.
I don't think she does it on an intentionally malicious way, but more like she is oblivious to how everybody else craves her scales and as such she just kept giving. She is mostly reclusive like the other Tapus in the present days though, so I guess she may have had a realization at some point (maybe while they were still on the island wars) and as such she mostly kept to herself. Olivia doesn't let you and Lillie get inside the ruins after all, saying not even pokémon really dared to come close to Lele and seems Olivia is the only one that can go to the ruins, gameplay aside.
