That largely depends on the size of the tank and if you already have any other tankmates? But generally speaking most similar size Malawi cichlids should do OK, as long as the food requirements are similar as well. Venustus is a predator and will eat other fish if it fits in their mouth, which is remarkably large - I have read reports that they devour Mbuna about a 1/3rd their own size.
Whatever you do: do NOT combine a single male with just one other single male of whichever species (plus females). That's a recipe for disaster. Venustus is not bad tempered as such, but it will try to dominate the tank (like a lot of other Malawi cichlids), and a fully grown Venustus male is definitely a force to reckon with. Most people in Europe that keep Malawi predators, keep them in (very) large tanks, combined with several other, similar sized, predators.
You would also do good not to put other Nimbochromis species in with it either. There is a bigger risk of hybridization, and agression may increase.