In this guide we will explain how to achieve the simple achievement of Disarmed what is part of the meta-achievement Glory of the Ulduar Raider with which we will get the Rust Proto-Drake (in normal) and the Ironbound Proto-Drake (in heroic).
This is not intended to be a guide on how to kill kologarn since for that we have other strategies. The difficulty of the combat is not altered since No. it's a hard mode.
The fight
For this combat, it is better to use the strategy of Down with the right hand.
Having clear the strategy, we will then begin by ending with the right arm (remember that it is the one that is to our left). As you already know, this will reduce Kologarn's health by 15% and the Rubble Elementals will appear that must be quickly tanked and eliminated. It is not necessary to remember to avoid Focused Eye Beam.
Once this hand dies, we'll have to DPS Kologarn as much as we can, without going over 35%. In case we do not get it the first time, we will have to finish with the hand again and lower it to 35%. If your life gets too low, you will have failed the achievement.
Once Kologarn has 35% health, we will focus on lowering hand health to 10-15%. At that point, we will kill both hands at the same time, which will reduce Kologarn's health by 2%, leaving him between 30% and 2%.
You almost have it.
Kill him and enjoy your achievement.
As you can see, it is a fairly easy achievement to achieve and will bring us one step closer to the Proto-Drake.