How to force spawn your desired Merc?

Hello guys, I noticed after running 500+ Dunes that KB Merc I was looking for was never being spawned. I tried exiling STR, INT, DEX and noticed that the only multi attribute merc I used to spawn, Sanguimancer, stop spawning after that.

Does any one has any clue how this works?

I don't know how it works, but I have noticed on the achievement that there seems to be a lot infamous ones I have not spawned. May well have something to do with exiling them or the ones you have hired and renowned. I'm fighting them pretty much every map and taking currency, beating them 90%+, so I'm not sure what would increase this, other than exiling more.

I have not looked if it is possible to influence the spawns or been watching any streamers, so not sure if the information is available. Most of what i've seen for the Mercs the information is a bit scarce. This is usually about the time where people start figuring out al lot of things though. If I see anything about it I will let you know. I want to find them for the achievement and it doesn't really seem to be progressing naturally, so will probably need to look into it, or find a way to speed farm them if there is no tricks. Going to look into it a bit more now that i've finished decking out my current Merc.