I was speed training my Meditite in Mt. Mortar 1F, and I discovered that there was something strange about the Rattata's I was fighting. They would move first due to me using a Macho Brace (as expected) but then I'd hit them with Drain Punch, fully heal my HP, and then get hit by a super-effective hit out of nowhere.
Here's a link to a clip I took, that shows this off.
https://streamable.com/gs9oq
It's not really a problem, just something weird that I thought I'd share.
-PeteMcf
Edit: Forgot to post the image of my Meditite, on the off-chance that helps.
https://imgur.com/a/WE2NO