I agree, about a Bretonnian Knight, but I know some folks dearly love them, and I can’t fault 'em for it.
Vampire, I can see a unique mechanic where it has limited max “green” health, or else its health is always going down - thus forcing it to “feed” to stay healthy. For careers . . . I dunno, if it’s a generic one, it could get one focused more on casting, another on melee, and a third that’s like a tanky bestial-type. Not full-on Strigoi; hell, it could be a point of the character that they never say what bloodline they’re from. Though . . . getting Saltz and the others to accept it would be difficult, far more difficult than anything save a Greenskin (which Bardin would definitely never accept; which I think is too bad, because Goblins are hilarious).
Lizardmen . . . I’ve never seen the problem there. There are three forms of teleportation used just in the base Vermintide 2 game - the Bridge of Shadows, the Skittergate, and the portal in the finale of Convocation of Decay that literally takes us into the Warp, and Nurgle’s dimension. Slann could easily use the Bridge of Shadows to send a solider, they’ve been known to fight all over the world (implying they do use teleportation), they do pay attention to stuff in the Empire and have agents there, and there are famous members of the faction who travel quite far (Nakai the Wanderer), and it’s even a special racial rule in AoS. And all it would take for justification is an Astromancer seeing it, or one particular Slann interpreting some prophecy that way. I still always insist a Skink, because:
- They’re more versatile in general
- They have a personality
- A Saurus is a big too big and strong for it to seem reasonable/fair
- They have a lot more options for weapons (specifically ranged, I’ve never heard of a Saurus using any).
- They’re adorable
Lizardmen aren’t even so exotic to Imperial citizens that they’d necessarily wanna kill it immediately, as several books mention that at least one exists in the Altdorf zoo, and they are known as intelligent, if savage, beings. Sotek is even mentioned as being known as an old god along with Manaan and Taal and Ulric.
Saltz would be suspicious, sure, but Lohner probably knows something of them (I still think it’d be interesting if he has worked with the Slann before, like a certain grey wizard in the Thanquol series), or else Oleysa, Kerillian, Bardin, or Sienna might. All it would really take is it saying “I hate Skaven and Chaos 100%” and someone in the know being like “yeah, that’s true, and they’re pretty much incorruptible” and that’d be enough, really. They’d be dumb to turn down an ally.
Another whole possibility (and bear in mind; the Lizardmen have not yet entered their massive war with Skavendom at this point in time), a Slann notices some warmbloods zipping all over the place fighting Chaos, and is like “Wtf” and sucks them to his location to find out what’s going on. Again - with beings who are essentially eldritch toads following a grand plan we cannot comprehend, some thoughtful writing can both explain it, and give an interesting scenario. Maybe there’s a prophecy of four (or five) warmbloods who are supposed to do something important, and the Slann is like “this is convenient”, then of course sends a Skink along to “supervise”. There’s not a lot of plot here to ruin; most DLCs involve just going after some macguffin or other (Drachenfels, Karak Azgaraz, Death on the Reik, Bogenhafen, Back to Ubersreik).
Regardless of what it is; we’ve seen necromancer strongholds, we’ve seen Dwarf holds, we’ve seen lots of Imperial towns and cities, we’ve seen forests, we’ve seen mountains and caves - aren’t jungles and golden temples something we haven’t seen that also follows the classic adventurer formula?