Broken Boss? (beneath The Depths)

So I'm on the final stretch of Beneath the Depths, and the boss fight feels extremely broken. The boss can teleport instantaneously around the room, and to the player. The boss also does a little over 1000 damage in around a second or so, thus liquidating me in a matter of seconds (I have 3400 Health). Also, leaving the chamber causes the boss to respawn with full health. I can't even fight back, as the boss teleports before I even can damage it.
I understand this is meant to be a tougher fight, this feels like it belongs in the Tower of Ascension or something, as this is extremely powerful. Is there some trick I'm missing? Or do I just need to git gud and recruit the knights of the round table to help me kill this thing?

________________________________

Update: Treasure Guardian either is teleporting to me, or teleporting me to it, but I honestly can't tell with how fast it kills me.

 

I can not work out what to do. I am an archer, and therefore rely on range and physically dodging, but there's no cover and no way to get away. I die in less than a second to his barrage thing. I can dodge a couple, but at some point he TP's mid-barrage and that's me done. I got him down to half by abusing bad ai by standing in the treasure room, but the he TP'd next to me and .6 seconds later I was dead. IDK what to do...

 

I also asked a question about this, the problem seems to be that his AI is that of a fast moving melee mob, but he uses the spell of an archer, so he almost never misses and does very high damage. I'd say this is a glitch, as he wields a bow but his normal attack is melee.

________________________________

Exactly. Even as a mage I couldn't do much because I had to spend all my mana healing from his ridiculously powerful arrow storm and couldn't attack at all.

 

I cant kill him either.. Im trying right now he just destroys me

 

My mage friend and I are in the same boat. It seems impossible to even get a brief reprieve to regenerate from meteor spamming and getting out of attack range. My health was 5000+ but without the proper elemental defences or elemnt weapon, our hits were not making a dent.

We should get a party together.
Just bot a reset scroll and Am going to rebuild my skills to help prepare for this boss. Any suggestions?
Any ideas for this boss mission?

 

Oh dear, this is the next quest I'm doing :P

 

Im having the same problem except the boss keeps on shredding me with his skill and teleports in the lava before i can kill him

 

Please refrain from necroposting.
Thread's locked due it it supposed to have been a while ago.