I'll just leave my comment here. At first it seemed crazy to me, but on the second thought... You'd have to keep all of the colours dark (with the exception for futuristic things). City could be done with few type of walls. Different coloured bricks and some smooth ones in similar colours. Some modern grounds, cool futuristic objects and A LOT of neon hangables that you would add a glow in tibia.dat. Still, mappers would be heavily responsible for the final look. You have to make almost everything look different, similar, normal and special at the same time. Ultimately it really depends on your idea of ot. If you only do cities in cyberpunk and the rest of environment kinda post-apo I think it's somehow possible. In my opinion the amount of work you'd have to put into that is not worth the result.
Btw. If you're looking for a person that would be able to do the job, I think many of a bit more experienced spriters here would be able to do that. It's just that what you are asking for now is not clear and you would have to specify what exactly you need. "Cyberpunk themed sprites" is not detailed enough. Even some tibia sprites could be called cyberpunk themed if used correctly.