Some ideas I've had (and likely others): The beasts of the new areas have gained the ability to pull aether from the surrounding area to shield themselves temporarily. To counteract this measure the Domans have created a special device that leeches away the aetherial shell over a period of 5 minutes, after which these rare and ferocious beasts become vulnerable to attack. This gives people enough time to spread the word via linkshell, people can teleport to the area and should have enough time to get to the beast's location. Perhaps while the device is being used a pulsating skyward glow from the aether dissipation that those near the area can see in case someone's being stingy with location info.

I'd also like to see these creatures have an affect on the environment while they're in the area. Perhaps certain fauna glow slightly when they arrive? A local ritual sight begins crackling with electricity or an obscure dried up fountain begins to spout water? Something that gives out a clue that there's something in the area causing a change (besides weather) and doesn't require you to fly in circles for 30 minutes second guessing if you missed it in some obscure corner or perhaps it spawned just after you finished a round of checking.