As far as I know they are no longer able to open doors, nor aggro mobs with the eye of zomm spell.....just fyi.
You pretty much can't cast/Mez on them or anything "useful" anymore. You can thank Live Enchanters for that thanks to sploiting Chromatic Haze and Twincast procs a few years back.
You say sploiting I say emergent gameplay. I must have mezzed, tashed, life tapped and all other manner of shenanigans to my eye_of_chaosflux over the years, I blame the high elf chanters for that nerf. Tho I'd think the abuse of echoing madness + eye to reset AA recast timers was overall more game breaking than the Haze procs.
Well I personally never called it 'sploiting' ... more so 'cheezing'... but yeah I don't think the masses would agree. Echoing madness was probably the most fun b/c it actually required some skill and a sense of time.
