I don't know if you guys know about this or not, but I just found out with a guy in Immotal
Follow this link, look at the bosses dropping the item
They are really easy to kill, with one EP healing, anyone can solo them (WF can solo without EP)
They response every 24 hrs, and hopefully they are not popular yet
They drop Mirages
all kinds of Celestial Stones, Time Book
some high level pots, and some really rare pots (like immune to damage in 12 seconds...), which can be really helpful in wars.
If you are bored before and after maint. you can get your self to their locations and kill them by yourself. Be kind and save us the pots if they drop, for wars.
Hope you guys enjoy