How Do we make Dream mirror a solid deck atm. We turbo out Oneiros backed by hypnogogia, oneiromancy and phantasms which are all quite solid cards. After that we just play a ton of good generic cards which the deck can facilitate i.e. Chaos, Branded, Dogmatika, unchained and witchcrafter.
What does this deck do?
It actually has some quite fun/ intresting things going for it in a more casual setting (though not even really playable in lower powered formats like Genesys). It has some interruption and protection mostly in oneiromancy, Verre and the extra deck. Between Albaz, The Fallen & The virtuous, Unchained, Mirrorjade and the Vice madame- unchained Abomination - Oneiros shinnenigans the main selling point of this deck is that it can repeatedly eat and break entire boards given the circumstances where you get to a position where you can establish some level of end board prescence.
Overall I don't think you can make much more of a dream mirror deck at the moment. You play enough dream mirror engine to get into Oneiros, your field spells and trap cards so you should really only play the number of dream mirror cards needed to get to that position then fill out the rest of the deck with options that can work with the dream mirror engine but does not directly compete with Neiroys normal summon slot and can compliment the dream mirror archetype and fix some of the issues with it. The deck is fun and very playable in a more relaxed casual setting but does not compete anywhere near any meta level