What's your "difficult" Pokemon?

[Black117]

The honor of the most annoying Pokemon for me (in-game) has ways been taking 2 days (well not exactly 48 hrs)or 12 attempts to catch Azelf back in Diamond. Like every time I tried to catch Azelf it setups a nasty plot and spams +4-6 uproars, swifts, and future sights so it pretty muc swept my in-game team. The worse part was the fact that every time I reduced its health and survived that whole onslaught, I'd take so much time that it struggled to death. Yeah this was when I was able to reduced Azelf's HP without having to KO while paralyzing it and using Timer/Dusk Balls. Basically I should have been able to catch it sooner but it most of my tries it just sets up Nasty Plot immediately and I have to reset since I'm not wasting money again.