I'm not sure, but am guessing you're talking about the damage-over-time mechanic? If so, you simply move into the appropriately-coloured room (as othes have said above) to remove the cloud effect which also heals your character and places a 'purify' buff on them. The latter I believe makes you immune to receiving the same negative effect again until it expires.

For more information about the fight see here: https://www.naeu.playblackdesert.com/en-US/News/Detail?groupContentNo=912&countryType=en-US#Thundercloud%20Kutum

I repeat.

Yes, I did not get acquainted with the mechanics of the fight, because it does not make sense anyway, my alt in an oasis (as it has most, and still better than "yellow" no dmg alts) dies from 2 hits from boss anyway, so will the aura kill me or the blow it doesn't matter, and I don't want to run 20 times with respawn anymore.
People who only stand get better drops than those who fight, so it's a waste of time.
All these bosses are a failure if you dont have ranged / fast movement class. 

I don't even bother going there. Got enough kutum boxes, and don't feel incentivised into dealing with an annoying super version that drops a rare item, that can't be sold.