Undergrowth Ruins Problem

I wasn't sure exactly where to post this, so sorry if this is the wrong place. Also sorry if this problem has been reported multiple times before. Once I made it to the boss, I killed the big slime and it split into 2, then one of those also split into 2, so when I finally got through the slime stage there were 3 bosses. The blood blocks one of them. This made it pretty much impossible for a level 58 to finish it.(the dungeon is for level 54...) If this was intentional, then the bosses fire rate has to be slowed because I was constantly being damaged and knocked back. I kind of doubt it was intentional but whatever. This needs to be fixed somehow. I had a better screenshot, but I couldn't upload it for some reason.

 

It's a pretty easy dungeon, you just gotta move around the boss, not walk towards it from 1 direction, also I dunno if it's intentional for there to be 2-4, but it happens with me a lot >.>

 

I beat it as a lvl 54 assassin... Just strafe the boss and you'll be fine

 

I killed him once when there was only one that I could easily strafe, but then I tried the dungeon later and there were 3 of them. Strafing didn't work with 3... Believe me I'm a assassin too. 3 bosses is too hard.

 

My biggest problem is the boss getting knocked out of the arena