I've played a Child-Thing, I've MC'd a Waterbearer for a one/two-shot. The Waterbearer seems almost out of place in the wilderness. They're political in nature, more-so than the Hardholder. The 'holder, and the Chopper to a lesser extent, is about dealing with big groups of people. Packs? Herds? I like herds. They spook easily, they eat a lot, but then can be led, with difficulty.
The Waterbearer did something interesting, it immediately divided the world into "haves" and "have nots", whereas before there were only "have nots". You might say "But MC, surely some people have something." And to that I say, well yeah. They have something. But for how long? How long do you need to possess a material advantage before changing your behaviour pattern from "get the thing" (the have nots) to "keep the thing" (the haves)?
I did something for the one-shot, which were kind of like love letters. I've spoken about them before, but here's the one for the Waterbearer (WIP)
You are the Waterbearer - You giveth. You taketh away. Blessed, blessed be your name.
Fundamentally, your presence alters the entire geography of the region. You own the last piece of potable water for a hundred kliks. Name three gang leaders who you’ve made deals with. What did you ask for, in return for access to your water. Two of them will have responded, ask the MC what they said. If one of the other players has a gang, you should definitely ask them. if they refuse your offer, turn to the MC and smile… They’re basically fucked, and they know it.