Bastion: Canon says 7'3"/2.2m, BUT the folded-out-of-the-way gun barrel from their altmode sticks up above their head; if you measure from the top of their head like you would for a human, I just kind of gesture at something around or slightly under 7 feet.
Which makes it easier to fit them into games' "don't be fuckhuge" requirements as well, since the cutoff is often around there.
They kind of do and kind of don't have a voiceclaim. Their voice is mechanical beeping, whistling, and whirring noises, but
I read the dialogue I write for them in the voice of Sad-One from Infinity Train, most of the time.
The Best One-One Quotes | Infinity Train | Cartoon N...
Wilson: 5'6" or so. Canon doesn't specify and has very stylised art, but he's definitely shorter than Maxwell. I wanted him to be fairly short but not super short, although I didn't go to the effort of recalibrating that for 1920s height statistics.
In canon he has a muted trumpet instead of a voice actor, which I translate into a squawky tenor voice that gets shrill when he screams. I headcanon him having an American accent, which canon is also vague about. I don't really have a specific voiceclaim that sounds exactly right, but NileRed is pretty close, between the pitch and the chemistry shenanigans.
The Ancient Fuelweaver: Well he's definitely a lot taller than the Don't Starve Together player characters but by how much is kind of hard to tell. We get a split second of him standing on the same plane as Charlie in one of the cinematics, and he's like a head taller than her there? She's quite short but he also has terrible hunched posture.
(Well, she's short before merging with the shadows anyhow.)
7 feet is the benchmark I go with for him as well but it's a lot more vibes-based than Bastion.
DST doesn't have voice acting for the NPCs either. At some point I realised I was reading his dialogue in the voice of the Beast from Over the Garden Wall so I just made that his voiceclaim. This is one of the less spoilery (for OTGW) clips I could use to show what he sounds like
Greg and the Beast (clip) - Over the Garden Wall
Moiré is 5'9" because it seemed like a good height to be androgynous at. Her PB is early-career Gerard Way and I didn't see any reason not to use his voice for her, except with a Canadian accent instead of a New Jersey one and bad sound quality even in person.
Gerard Way being cute and weird for 4 minutes +a lit...
I picked her height first and her PB afterwards but got it accurate to the PB by sheer coincidence. 🥳
Purple's height wobbles around a bit but 5'8" is the number I usually go with. A very middling height by human standards, in between the averages for cis men and cis women. The full range that it usually wobbles within is 170cm to 180cm, because that's nice and round in metric, and in imperial that's about 5'7" to 5'10".
And I already had too many characters who were 5'9" (in addition to Moiré, there's also Aggie and Yochelm) so that's what pushed them slightly more to the shorter end of that range.
They don't have a specific voice in my head. The voice range they have is "could be a contralto, could be a tenor" to make it more difficult to infer things about what else they've got under the all-concealing environment suit (being a shapeshifter this is at least somewhat deliberate IC), and it's hard to even find voice actors who fit that.
Marin Miller, Namari's voice actor from the English dub of Dungeon Meshi, is the only one who springs to mind.
I didn't do a height lineup because either using the provided human figures OR uploading my own for Fuelweaver and Bastion would look ridiculous. You get rambling.
As previously mentioned Yochelm is 5'9" and I don't have any particular idea what he sounds like.
Wormwood I put at six feet even, because I want Maxwell and Mighty Wolfgang to be the tallest survivors and they're like 6'6" or something in my mind, but I still want Wormwood to be tall and gangly.
In canon he sounds like didgeridoo noises. I'm not sure what that would translate to but I'm sure his voice sounds very peculiar. I've flirted with the idea that he speaks with an Australian accent, although given that his reference point for the English language was pseudo-Tudor-British pig people I have no idea where it would have come from.