Chansey
So I am assuming Chansey is not soloable?
Answers
You have to bring a friend in to share the burden of beating on such an adorable Pokémon, so that you can look at your friend and go "We will never speak of this again." and you only bear half the shame of punching the adorable little fat pink egg Pokémon.
But, if you have no shame, no soul, no conscience, not a drop of decency in your body, then it's a pretty easy Solo.
(What? I watched a YouTube video on it! I certainly didn't grab 3 "Catch 1 Chansey for 3 Rare Candy Quests" then went out looking for a Chansey raid to do. And I certainly didn't solo it in just over 100 seconds with my two Perfect Level 40 Machamps (and that is not a HumbleBrag, because I've actually got 3 Perfect Machamps now, so mentioning that I have 3 is the HumbleBrag wait I just ARGH dammit), only losing 1 because my dodges just weren't being recognized. That certainly isn't what happened today at all, no sirree bob it was NOT.)
(Narrator: It was. It totally was. It was even worse than that. He didn't mention how he laughed and kept on saying "Wobble Weeble Wobble! Wobble Weeble Wobble!" until finally "Weeble Wobbled AND FELL DOWN!". It was not his best moment.)