Take the Aspect of Charon axe, which causes your Omega Specials to detonate your casts

Start with Apollo's keepsake and take Lucid Gain, which gives mana for standing in your cast when it finishes.
Cast on yourself then use your Omega special to instantly detonate it.
You now have infinite mana and can spam Omega Special across the screen.

Combine this with Aphrodite's Heartbreak Flourish, which is the hardest hitting %damage special boosting boon. You can then go for any of the Poseidon boons which satisfy the Aphrodite+Poseidon duo boon requirements. The duo boon causes Aphrodite boons to treat all enemies as nearby, which means 200% boosted omega specials across the entire screen.

I used this to get Night's Champion
Have fun.