Want me to spoil Rivulets campaign for you? Yes? Ok:
So The Rivulet may be some kind of messenger kind of like spearmaster, considering the fact they already have the mark of communication. Basically when you meet 5 pebbles he is dying because of the rot and asks you to take out his core that allows him to live and try and flush out the rot (btw thats the cause of the extra rain in this campaign) so moon can repair it. You find it in this new area called the rot. If you do, his core basically gives you the ability to do superjumps, and you can go into moons old superstructure and plug it in, restoring her back to a normal iterator
