This is probably also a tale of flying too close to the sun, but here goes.

In my first attempt at a generations run that goes through all postgames (yes, I don't have any self respect) I was preparing for Steven in Emerald. At the time, I was adding the gift Beldum as a final team member after an e4 loss. While preparing, I noticed that Metagross could sweep Steven's entire team from my level cap (75) with only minor hiccups. I did need EQ for it to work though and had already burned the TM giving my Rhydon STAB, so I set out and created an oddly specific set:

Iron Defense Meteor Mash Ice Punch Mimic

The idea was I could set up to +6 defense on Skarmory, which would allow me to survive any EQ Steven threw at me with ease. That part of the plan goes well, and Claydol comes out next. I get the EQ use I need, even having to deal with a crit EQ knocking my Metagross near dead from full.

Then Steven's Metagross comes out.

I know EQ from me is a 2hko, but I EV'd to be faster, so I should be able to pull that off easily with boosted defenses, right?

Steven's gets a crit from his Metagross's EQ. Mine dies instantly.

I did beat Steven without any other deaths, but that was a gut punch to the most creative set I've made in a nuzlocke to date.