I think I see a couple things that would help you, as well as some of the suggested things, so I'll just list them here:
Improved Miracle: You're using a decent amount of quantum towers as well as a full set of supernovas, so this card should easily fit in, cost wise at the very least. Could definitely help give you the couple of turns more you might need to get the poison damage to kill.
Jade Shield: I'm unsure if you want to keep this w/o permanents or if that's just the way the deck went, but I think this could be a helpful addition. I chose this over the Light reflective shields for two reasons: 1-The extra -1 damage per creature as well as the cost. It's life quanta which is completely untapped with your current design. Would help mitigate damage as well as deal with enemy poisons/fire lances/etc.
Black Hole: It uses the untapped gravity quanta you generate as well as healing you. If that wasn't good enough, getting them out early vs a multi-element deck, especially a rainbow deck, can easily win you the game by slowing them down. I think this is almost a necessity vs rainbow decks considering the massive amount of healing they usually pack, whether it be in the form of boneyard/ffq+bonds, shards, and or miracle.