Washing + Pink Bean

I recall reading that PB's damage reflect works in a similar manner to Balrog's damage reflect; i.e. it has a very obvious animation, it has a set duration and cooldown, and he'll almost always use it immediately after it cools down. If that's the case, then you can have one person act as a timer and remind everyone when to stop attacking. Although there's a lot of complications with that. Balrog can be easily defeated within the given time frame, so squads can afford to wait around while Balrog casts DR for the first time. Not so with PB. And then there's the average player's capacity to deal with all the things that you have to watch out for at PB. At Balrog most people can't even do something as simple as stop attacking. PB is confined to a less nooby crowd, but between all the dodging attacks and making sure he stays facing one way, it's really impossible to make sure everyone can stay alive.

Even though most of the time I like to call BS on people who claim that having more HP = more survivability, PB is just way too much.

I haven't fought Balrog yet, but I've fought quite a few Lilynouch. And from what I know about his damage reflect is that the reflection starts right when the animation for that skill starts. I've not yet been able to stop before reflecting damage at least once. The difference is that Pink Been will do it the whole fight and it will kill you. There's not really enough time on the timer to just not attack for half of your encounter with him, but if you do attack everyone will be dead. It's pretty unfair.