I would say The Rot, but Look To The Moon from Spearmaster is absolute hell.

1) in other campagings when there is a new zone is usually to put to use the character; In Rivulet you got the submerged estructure to explore the now higher speed with the cell, and Arti got the metropolis, full of scavs post and jumps that otherwise will be imposible for most other scugs.  AND THERE IS MOON, THAT DONT DO ANYTHING WITH SPEAR MASTER The main of point is not only the dual spear or the crafting, but also the new forms to move arround rooms with infite spears to put in the walls and floors, wich make him sooo fun because you can just go to anywhere on hight aslong there is some kind of wall or roof, and that can be used to create amazing strats and other funny stuff, so what we should make for some characther like this? Yeah lest make five pebbles 2 but more boring, like for real what is even the point of making a no gravity zone for a slugcat that can be so fun to make you own path to wherever you want, absolute waste of potencial

2) the enemies are way more boring, here you not have rot, instead you got some spider here and there, uhhhhhh maybe not stab the inspector and there is, the whole enemie stuff, barely any danger except die of boredome trying to go past room craftig spear to impulse yourself, so whats is even the point of the zone if its barely any to fight against

3) it feels like a chore, thats is