The boss works as intended. It is supposed to be a direct damage check for the party and a tankiness check for the, well, tank. The boss gains 5% pAtk and 5% damage every second whilst losing defense.
Since the boss increases damage every second by 5% and patt, does the damage dealt to him by 5% and defense decrease by 5% every second?
Players will incrementally deal more damage up to their maximum, which is reached at 20 stacks regardless for gear (as the boss then reaches 0 defense).
For days you could kill this boss without a tank, it was hard to find one that was powerful enough.
We, as the team, are not here to tell people how to play their classes, but the instance was tested with red plate gear from ROFL as knights and champions; the latter struggled hard in longer (longer than 15 seconds) fights, while the knight had a decently easy time for about 16 seconds - from then on, immunities can be used. Golden Tank gear extended this time to more than 20 seconds. Other mechanics that reduce damage heavily can also be employed to increase the fights length further.
The boss is supposed to be killed within the first 30 seconds; our data shows that there was not a single run of heavily undergeared players that kited boss one but made it beyond boss two. This is a non-issue as, comparatively, the iron rune warrior is the easiest boss in the entire instance. If your tank couldn't survive this boss without major hassle, they couldn't survive locathas freeze.
For days you could kill this boss without a tank, it was hard to find one that was powerful enough. And now that these most ambitious players have obtained artifacts by defeating this boss along the way without any problems, you will now "patch the hole" preventing weaker players from doing so.
It is indeed a very fine politics, very kind of you to wait for us strong players to make artifacts and now you are making it difficult for the weaker ones.
With the addition of refined artefacts the grind (overall) will have to be re-done by the "big guys" too; I realize that the changes may seem frustrating without specifics but it is important to note that the devil lies in the details here.
That being said, the entire dynamic that one could obtain an artefact without running the full instance was a design flaw; one that had to be fixed. The solution to create an upgrade so that players are incentivized to fully run the instance is just the natural progression.
The base-equipment for running kalin comfortably is a golden ROFL set.
