The only time I've paid attention to a Loudred was in PMD: EOT/D/S, and while he can be a tad annoying there, he is still rather likable for some reason.
The below user dislikes Tapu Koko because (spoilery reasons described below)
after you beat the final Trainer before the credits, you are forced to fight it without getting a chance to save beforehand and preventing you from soft-resetting if you either kock it out or care about getting a got Nature (unless you want to battle the last Trainer over again that is).
...Though if you do knock it out, you can go to the Ruins again and re-battle it, just a little tip.
Disclaimer: BAG does not dislike Tapu Koko, in fact it's still BAG's favourite Tapu because dat design tho.