Thank you!
Wow, but that is designwise worse than Black Castle now. There is a reason you do not see many "xyz" people required quests in open world or even 6 ppl dungeons (also you do not change things to be more customer unfriendly than they were without giving info or a choice)...but they seem to ignore that willingly. Instead of just fixing it in a fair way (or do you consider all who got it before the change now as exploiters?) it got fundamentally changed. At least you do not need it for the "solo" targets of interest anymore. If you did it like 6 people doing it "properly" giving some extra reward lootwise, but still left it doable for smaller groups, then fine. But not like this, please, basically enforcing a control where it is not needed and is just forcing the customer to waste time on content others have done or been gifted as solo or two people content.
Does it also work, if there is a raid and only 6 people summon the boss? or do just the 6 on the stones get the achievement? Can people get another red gem and help others to get the achievemnt done or is it a one time only thing now?