Placing a Pokémon
Isle Avue's goal is indeed to increase the happiness of the Pokémon who are placed there. The longer they stay in the hot springs, the happier they will be.
As you maybe know, happiness can take a value between 0 and 255, and has some interesting effects that I will let you discover on the corresponding wiki page. When touching a Pokémon who is staying in the hot springs, you can evaluate its level of happiness on the moment, depending on the displayed text:
- "Looks quite fond of Isle Avue": Between 0 and 99.
- "Your Pokémon seems pretty relaxed!": Between 100 and 149.
- "Your Pokémon looks mighty relaxed!": Between 150 and 199.
- "Your Pokémon seems so relaxed that it would be impossible to be any more relaxed!" : Between 200 and 250.
Do note that you shouldn't let a Pokémon more than 24 hours in the hot springs. If you do so, the dizzy icon will appear above the Pokémon's head, and its happiness will start dropping. So remember to come back and remove your Pokémon from there before its happiness starts to decrease. If you forgot to remove it, you will have to touch the Pokémon to reset its state. That's when the message "Your Pokémon looked like it had taken all the heat that it can handle! But it seems to have perked up now that it’s seen your face, hmm?!" will be displayed. If more than one Pokémon in the isle section was dizzy, touching one Pokémon will reset every Pokémon's state in this section.
Placing an egg
Another interesting point in Isle Avue is that you can also place eggs in the hot springs. If you do so, it will have the same effects as if you had the eggs in your team and were walking with them: they will slowly hatch. So if you don't want to handle the eggs yourself, you can place them on Isle Avue and let them hatch there.
Using Poké Beans
Placing Pokémon Beans on this island will bring some positive effects for the Pokémon and eggs placed there. The increase of happiness will be doubled for the Pokémon, while the eggs will hatch faster.