Ok what about Dash Kick → Flow: Call from Sky W+F → Space. Flow: Call from Sky is the PvE iframe I was talking about earlier and Dash Kick is a no cd knockback. I didn't test it in Pit of the Undying but I checked the animation flow on my 0 attack speed sailor Ranger and there is no way Flow: Call from Sky isn't fast enough to (PvE) iframe the counter-attack roar after the Dash Kick knockback.

Sorry to resurrect this but the problem is still there...
The problem about this mechanic is that is so strict that one single fail means that the fight is over and you lose.

There is no a second try, and many classes have problems with the CC in their skills, or are slow to reach their back and hit because the animation is so slow or Gotha Rensa have already rotated over him to face you (still in his headbutt animation).

So right now, we can say BDO is not Elder Ring, or Dark Souls, why Pearl Abyss is so obsessed with complex mechanics that are not explained anywhere in the game?

Maybe a solution for this mechanic is to not be a "if you fail you lose", and just prolong the fight, and not to be an almost instakill.
Same happens to the "Simon" game of Duran, there is no explanation, and if you do a wrong hit, Duran get a buff that lasts until the fight ends.

There are classes that does not have all the CCs needed for him, and these bosses can must be killed by every class in the game because the  Pit of Undying is a "general system" included in the game for all the classes.

One way to improve the design with respect to class differences is to make the challenges / opponents fit the class.  More work on PA's part.  But with that replayability goes up by a factor of the number of classes.

Same goes with the black shrine bosses, but at least there you can pick which ones to fight.

Gotha Rensa doesn't have rng mechs it's depending on his hp %  and I never fail the floats 4x in his back. Sounds like a skill issue. But it should be 3 tbh since u can only fail once and this at about 3x per fight 

I hate this boss... It makes me angry.

I simply dps him down without using floats. It's a bad/unfun mechanic

There is also the problem where when you go behind him he does an insta 180° no scope stun and melts you. It's really not fun on archer so I usually do it on drak where I have better repositioning and cc options, still fails sometimes due to said problem

i wonder how you do that, because for me, this guy is 100% uptime have float mechanic protection where he doesn't take any damage and going into frenzy even before first mechanic round exprire if i trying to burst him.

Its very funny when he doing this on last float hit on 3rd round  of mechanic.

Did something change with this guy? Been killing him for weeks now. All of a sudden this guy is one shotting or stunning me. Then causing non stop explosions everywhere. I haven't changed anything.

Just trying to do the guide from blackdesertfoundry pushes him to below 30%. It seems I have to kill him within the % checks. While he's trying to headbutt or I can't do this fight.

Gotha Rensa

• Gotha Rensa first appears in your daily challenge once you reach PEN Insignia.
• At about 80%, 50% and 30% HP, he will sheathe his weapons and switch to using a shoulder charge instead.
• Each time he does the animation for the charge, you need to go behind him and land a knockback or float CC.
• As soon as the CC lands, he will do a roar attack in your direction which you must dodge because it deals very high damage.
• He will repeat this 5 times and if you don’t CC during the charging animation at least 4 times, Gotha Rensa will instead do a non-damaging roar attack and will now become unkillable for a period of time.
• If you are hit by Gotha Rensa while he is unkillable, it is an instant death. If you manage to survive, he will return to normal but start doing explosion damage all over the arena, so if you fail the CC, it is best to just start again.
• During the final phase, he can also do a large red AOE attack on the ground, and his other attacks will also change for each phase.

If you want to cheese him:

First he runs up to you: In this phase you can use all your  skill without triggering a mechanic. If you are lucky he does a long animation attack where he smashes the ground with his axes (if you are stuggeling simply reset the fight till he does this animation).

In the  next phase he attacks you with a charge animation: Don't use any float skills, since you want to not tigger the float mechanic. You have to (almost) kill him else you can't  finish him off in  the explosion phase (you can reset if he has more than 10% hp). His charge attacks in  this phase CC  you and deal  alot of damage, i recomend to simply dash behind his back while he does the charge to avoid the hit and get back attacks

For buffs i recommend: species damage lightstone set, caroline buff (if you are in heidel) and exquisite cron meal