For the boss fight at the end of Azurr Dream Realm (in Story Mode), you fight a copy of your own team.
I would highly recommend that you copy Artifacts (and Spell Gems?)
My team (and I assume most teams) have synergy between their innane creature traits and their artifact traits. When the enemy is missing the artifact traits it messes up the synergy and makes for an anti-climatic fight.
I know that you don’t typically like giving artifact traits to evening, but you should consider making an exception in this case. (For the sake of the boss fight!)