Indominus Rex Alpha - Best Game Changers and other cards ideas?

Hello, I have been meaning to make some upgrades to my Indominus, Rex Alpha Voltorn commander deck! I want to add 3 game changers (Thinking cyclonic, rhystic +1)

Deck List: Indominus Keyword/Counters // Commander (Indominus Rex, Alpha) deck list mtg // Moxfield — MTG Deck Builder

Been thinking about Dinas Guidance and Madame Null! Any other ideas?

Everything is greatly appreciated! 😃