What I am thinking here is an ability that completely blocks the usage of AOE abilities on a targeted player for a short time. Unlike Negate I was thinking of a single target debuff completely stopping all AOE attacks including impulse, batswarm, nova... everything. This could increase the likelihood of guilds and groups working together to stop the zerging strategy before the servers become useless and completely dead.
Perhaps this is a temporary solution or a bad one (that's really up to the people who keep playing and to be honest I'm not sure I will unless this issue is resolved very soon), but it is an option to consider instead of JUST nerfing these abilities.
Krojick, DC Sorc PC NA
Milámber, EP Sorc PC NA
Brunack, EP DK PC NA
General Mark Shephard, EP Temp PC NA (Worst temp NA XD )
Krojick Nightblade, DC NB PC NA
Others...