Chance to spawn cultists

How is this stat works? Does it increase spawn chance if tower kills, or just increase chance the next wave will be cultusts?

In my Tests it seems to be a global +stat that increases the overall Chance of a further Wave being a cultist Wave. My max was so far +42% but it hadn't much of effect... possibly I was just unlucky or there is a hidden cap for max +cultist Wave... Note that cultist waves seem not to occur during Bonus rounds just during normal game... possibly via Necronomicon they could be summoned but i wasnt able to Test yet.

Ok i see, ty for your information sir. I will do some tests too and will share what i got

Andy posted on Discord that the base chance is 16% and the max spawn rate is 50%. WRONG: He also said the items don't need to be equipped to trigger the increased spawn rate, which surprised me. Edit: added "Wrong" before my false statement. I misunderstood what Andy said.

Huh? So you need just to keep it in your inventory? Btw can you please share discord link?

Just to clarify, the item needs to be equipped for spawn chance to have an effect, it just doesn't matter which tower.

The Discord link is in the Mazebert app at the top of the multiplayer screen. Home > New Game > Multiplayer > Top of screen

Forgot i am already in it LOL. Yeah just found your post in discord. Ty so much guys