[Erati]

The Overseers dont depop like that after 3 days.

Also killing the 3 day Noble ( the one on the left of the doorway ) does NOT spawn an Overseer. Overseer only spawn off the 7 day Noble death and thats how you can 'count' how far the cycle has gone.

Overseers do not start to depop until there are 4 Overseers up, then when you kill the 7 day Noble that would have spawned a 5th Overseer the very first Overseer that started the cycle will depop when a new OoA spawns.

I believe 4 Overseers of Air is the max you can have up and it will produce Nobles everyday with some days having 2 and eventually some days with 3 as those 7 day Noble timers begin to overlap with the 3 day ones.