I haven' heard the Dominus, but I have heard the Venustas and own Sky. IMO Venustas is far from beeing natural cable - it has been noted by many ppl on this and other forums who have tried it. Basicly, it is closed in on top and not very transparent.
Of course, with some brighter, harder sounding stuff (like Cmo's Theta CDP) it actually may help. But you cannot use this cable as a benchmark. Almost any cable compared to Venustas - be it Valhalla Sky, TA Reference, Fadel Coherence - will have an elevated treble response for that reason.
IMO you should try first before you buy. I have tried many top tier cables before getting the sky (namely Valhalla, TA Reference w/MM, Fadel Coherence) and much preffered the Sky, as the most "complete" sounding of the lot. Same for my Everest speaker cables. I'd love to hear the Dominus stuff though.