presented two types of this "RAID" on Oramond, I don't know your first mind so...
You mean Renegade Quaras, right? this is part of the quest Twenty Miles Beneath The Sea and world change (ask 'sea serpent' to NPC Guide about status).
These quaras appear after the world kills 3000 seacrest serpents, but it may disappear in two cases:
- When 1000 quaras are killed (all types included).
- When someone made quest with achievement "Snake Charmer" and give back their stolen orbs to the NPC. Only one person per world change can do it!
then Seacrest Serpents reappear and you have to kill 3000 of them again for world change with Quaras.
When it comes to the Quaras Scouts raid on Wester Plains, the only information I found on the internet is
I've hunted the spawn ALOT and I can confirm that it seems very random. The quaras will appear at any given time and also for any given time. I've seen quaras appear and spawn for over 6 hours, but also had them disappear again after 20 minutes... there's no logic in it so im guessing random.
source: How Quara's raid in Oramond West work? -Reddit-
Hunting here is specially good when the Quara Scouts raid is active, because it greatly increases the experience gained. This raid can start (and end) at any moment, but it's not announced