signal basin
as a random event players can come across an extra well defended marauder outpost with a large vault door in the center. interacting with that vault door causes a bunch of extra marauders to spawn and attack the vault, afterward spawning a miniboss. following the death of the miniboss the vault opens spewing extra gold out and maybe a handfull of high-tier jokers. as for what these minibosses ARE i had a couple ideas;
Marauder Honcho; a large marauder that has the effects of one or more jokers (more and higher tier jokers depending on difficulty) moves around like a player and can have weapons other than the base quad
Marauder Shaman; a marauder who's able to cast spells, not like the player can of course but a special spell for each element.; can shoot out a fireball, call down some lightning strikes, temporarily invert a player's controls or just make their camera wobble around, leave a bunch of hostile cactus mines or spray slippery acid around that acts like ice. can only use up to three of the spells just like a player though, starting with only one spell on normal and going up from there
i had some other ideas but i couldn't flesh them out enough to justify giving them a proper entry.
main steeple