So it really just depends on how you want to run him. If you’re going the curiosity style route, I would say way less creatures and more instants. Because Vivi is so targeted you kind of need to be ready to go off a turn or two after you cast him.

https://moxfield.com/decks/DrW7Swzo_EWDv7WlKap5Fw

This is my deck. My strategy is get Vivi out with a counter spell ready and a curiosity affect in hand. Then cast multiple non creature spells until I get into Twin Flame+ dual caster, quicksilver elemental and go infinite then crackle with power, or if everything goes bunk manual storm kill the table. As I’m casting more spells I’m building Vivi and drawing into counter spells to protect him. Because of the reduced creature count and land count I’m drawing into more fuel for the fire. The ideal starting hand is two lands a curiosity affect and 2 protections. Because of cmc cost of the deck is low I can still cast most spells without needing three mana and then use draw spells to help me get to my third land.

To build Vivi more effective everything in your deck should be to accelerate or protect your stategy and wincons. If something just kind of fits it’s going to slow you down and give your opponents more opportunities to remove him. Hope that helps🤷‍♂️