Honestly, you just have to run through the dungeon a few times and you would see all the issues with it:

1. During the 2nd phase of the last boss (light matching phase), the colored crystals will randomly not follow anybody and just fly off on it's own even though there's no rocks or lightning.

2. During the 3rd phase of the last boss (lava phase), if you are playing on very low or optimal settings, you won't be able to see the true size of the lava on the ground.

3. During the 1st phase of the last boss, the left boss (lucretia) will randomly run to a person on the big boss (dinosaur) even though that person never attacked lucretia.

4. When you finally beat the boss and complete the dungeon and go through to the final room to turn in the weekly quest, you will sometimes not be able to interact with the pillar to turn in the quest no matter what you do. If you go to character select, it will kick you out of that room and you will have to do the dungeon all over again.

5. When you are lucky and are able to interact with the pillar after beating the boss to turn in the weekly, even though you beat the boss on the ELVIA server, it gives you the option to select 1 of 2 quests to complete and there is no indicator which one is for the elvia weekly turn in or the normal weekly turn in. (The top option is the Elvia weekly turn in) I understand that you want to give players the option to get the normal reward on a different character if they are doing it to help their friends on the Elvia version, but at least put the words ELVIA and NORMAL next to their respective turn ins.

There is so much more issues with this dungeon that is just not player friendly and IF your development/design team actually played the game, you would see the issues.

Oh by the way, you should play the rest of the game too on every single class so you can see the imbalances in PVE and PVP. There is no reason why 1 dps class can get 3x more trash loot than another DPS class with the same gears at end game grind spots. There is no reason why an Awaken Sage with 630 GS being able to 2 shot people with 680 GS using full human damage crystals and not be penalized because their base accuracy is so high or why they are able to destroy everyone behind barricades in node wars.

JUST PLAY THE GAME YOU DESIGNED AND DEVELOPED!

I think at this stage everyone knows that this is just another money grab, all they care is profits, they create problems only so that you can solve them using pearl items.

The dungeon was so overhyped, every person that I know that have tried doing it had a negative experience including myself (I cleared it once on nomral pre-nerf).

the dungeon is bad because I can't faceroll through it!

Right...because complaints about bugs or at BEST a shit design choice is all about being able to faceroll it.

Did you even bother to READ the complaint before going into white knight mode?  ALL ofthe points in the pointed section is absolutely correct.  Having a BUG that prevents you from collecting the reward for beating the boss and having to start all over again is not about facerolling anything.  It is a legit issue they need to deal with...like over a week ago when it was known to be an issue.  Not being able to tell which reward is which...once again is a serious issue that has NOTHING to do with facerolling...and a simple TEXT change would have fixed that.  Why it has not been done yet is rather unacceptable.  

As for the boss mechanics...havin the mechanic be that they be kept apart and then having it so they can random agro anyone and end up merging is a bug if they are not complete morons at game design.  Having the lights fall off at random is a bug unless once again, they are utter SHIT at game design.  Having the lights fall off if you use ANY movement skill is a bug unless once again shit game designers.  Having the lava field only be indicated properly at certain graphic levels...once again bug or shit graphical designer this time.  

1- they don't follow because  member of your party atacking boss, you cannot do it.

3 - this is happening because member of your party using taunt ability, if you use taunt of any of 2 bosses other will also get taunted.

4-  you don't have to do dungeon again, you can re enter as long as there is atleast 1 person still inside

5- there is no Elvia or season final room, as long as you have proper key you can do whatever quest you want.

Funny how forum experts doesn't know this generic information, oh wait right unlinked/private account cannot even do such simple dungeon as vaha.

Some guys from PA actually did play it on stream when the dungeon got released. Ironically they did not manage to finish it kek...

8 months later you go and dig this topic up?  Why everything the OP posted has changed.