Chaining baium didn't stop the cast, it just delayed it, he would restart the cast half a second afterwards, no matter how many times you chained him. Unless you had like 6 tanks chainlocking him it would be impossible to permanently stop the AOE. I wasn't here for the very early baium attempts but from the ones I attended chain was only used as a way to delay AOE for 1 second so that the bishop would have enough time to fully heal the party. After a point there was no need for chains at all, the surplus of EEs/SEs meant that the bishop always had mana so the titans always had full health when he started the AOE cast. Yes it was a bug, and it's probably not supposed to be this way but aside from some very early tries, baium has been on autopilot mode for like 1,5 year now, probably more. From what I understand the bug used at zaken just straight up broke him, I mean I heard he reached 10% in like 30 minutes? Really? Either way, if it is proven that china also abused that bug for their kills, I guess they should have their drops taken, I mean that's the most fair thing in my opinion.