Ah, the joys of fighting arguably the toughest of the Gate of the Gods boss, Meraxis, God of Bliss. In case you missed it, Meraxis has a punishing Trait, called Iron Will. Which reads: "Your creatures start the battle with 100% more Health, Attack, Intelligence, Defense, and Speed. In addition, your creatures act as if they have 1,000% more stats." Yikes!
If you want the "cliff notes" version of my strategy, here's how I did things: you'll notice my team is largely the same as the team I currently use as my main creatures, including my Djinn Pyromancer, my Nether Chaos Guard, and my Omnipotent Deity. But it's the other creatures that matter most: a Dragon Scout, Dragon Revenant, and Phase Knight. Basically, the Phase Knight is mostly there to keep residual damage to a minimum, and the Dragon Scout and Dragon Revenant are there to reduce the enemy creatures' Attack and Intelligence as quickly and effectively as possible. Assuming my creatures can withstand the initial onslaught (which is by no means a guarantee), once the enemy creatures' attacks and spells are less than lethal, it merely becomes a balance between weakening their defenses and keeping my own creatures alive. Naturally, creatures taking more damage as the battle progresses only complicates things.