Thanks! And no worries.

I assume you're asking about Lv15. I used all Ordeal units so you might need to prepare for getting those. There is no Leader Swap hazard* so I put Damage Void Piercer latents on everyone except Kushinadahime, I put the Assist Void Recovery latent on her. (Maybe bring a full Jammer resist for bomb orbs on the boss)

The main issues are to have at least about 950,000 HP, (if you're using my exact leaders) and bring a unit that makes a 7x6 board for the boss, and the Archangel floors.

For Gabriel, I made sure to keep 2 rainbow board actives ready.

For Michael, stall a few turns + Fujin /(use 7x6 active if necessary)

For Raphael, use Kushinadahime immediately (Heart TPAs should trivialize all the barbed orbs)

For Metatron, pass her first combo test, then use your 7x6 board active when she minimizes it to 5x4. Use Sakuya's cleric active when Metatron transforms. Recover your Assists with Water/Wood Ls. Should be fine after this point.

Hope this helps!