Imperial Assaults Where & When?

[Deli]

I played ~ 2 time at camp tranquil, 3 times at horizon.
I notice when the moon (just shift) to upper right corner (these 10%) moon phase alfgar will pop.
There will be 3 waves. If you fight good, they will withdraw within 10 mins. Seems like have to kill certain amount of captains (not certain). If the number wasn't meet, they will win after ~20 mins.

You don't need to kill to earn the reward. All you need to do is sign up. then you can go to a quiet corner to craft.
They aggro to anyone who sign up, regardless your rank.
Also, when we say at Camp tranquil, it's not exactly at the camp... it's NW of camp tranquil, north of camp horizon for example.


BTW when Alfgar pops, imperial will attack. However, it's not mean when he's there, imperial will keep attacking. After a while, Alfgar's chat will be different and saying we won and some adventures fight them off... so don't tele to Horizon when you see Alfgar right away. Confirm with him first.
It also happened twice to me he told me we are under attack, but when I go to horizon, it's nothing for 1hr. then when I came back to talk to him, he changed his dialog...