I can only recommend you to rethink your plans. Control Vet and Creep Abyss are both very expensive archetypes requiring a significant amount of legendarys, you can’t realy build one of them while saving for the other.
As far as Creep goes you also have to consider that a bunch of main cards for the Archetype in form of Klaxon, Sphere of Darkness and Obliterate will rotate out of standard format with the next expansion and even if there will be new cards to fill the void, nobody can say how good of a deck creep is going to be. And even if it’s good, due to the rotation there is no point crafting said cards now when they will be gone in a month or two.
If you like Cyph your probably better off going for him instead of Creep Cass. Paradigm won’t rotate out for quite a while and between Thunderhorn/Lost in the Desert, Paradigm, Aymara and Blood of Air he is in a solid position right now. He is probably also the General who will be affected the least by Falcius leaving standard play since he has his BBS to make free trades and stay alive.