Controversial take: Remove Gunnhildr's Blade titles from everyone and fix the exploit

[Drakonic]

I can explain it to you since it's not an actual exploit. Some youtubers explained it well.
What you need:
Ordained potion, Lost Excellence (25), Lost Flare (20), Chainspell (20), Banner of Noble Ends (10) and classic Intelligence potion+Your job buffs if you have.
+Don't forget Dispel (3) or Mirror (1) for Lyon/Menenius. Also take a potion of resistance since you're going to have low HP

First step:
Use the Bozjan potion Ordained
Aggro the dummy to be considered in combat
Load your set if it's not yet -> Use Lost Excellence
Swap to Chainspell -> Use Chainspell
Swap to Banner of Nobles ends
Int.Potion then zone in around 5 seconds before the duel starts.

Second step:
Use your job buffs + Banner of noble ends.
Swap with font of magic -> Use Font of magic.
Flare star and watch as the duel opponent melts. (Lost flare will tick at 300k)

I believe that's all. There's no real exploit like "clipping into a wall" but a massive imbalance due to lost Flare, you need ~75 space and the max is 99.
Lost Flare will benefit from a short window of 10 seconds and 5 Bozjan buffs except it will apply for all ticks, the boss won't last a minute and you will see one mechanic or two top.

An actual "exploit" is that a Dancer can grant you buffs like Lost Dervish, Devilment and Technical finish.
Attacking the Dummy allows you to use Lost Excellence&Lost Chainspell and to get a much wider window for Lost Flare but you can do it against a monster and since you don't need more than 80 space to fit all the buffs, in theory you can do it in a duel.

In theory, sure, but does anyone actually not use this exploit?

It's funny how everyone here is trying to portray this not an exploit. I wonder if that's because they secretly used it to do the duels to get the title or field notes.