The most challenging maps for you.

then what do we do next?

After that, you have 2 options.
1. Go through the dungeon on the swamp respawn to Sandro and visit his blue tent. Then kill Jela, take the brown tent, and go further where Sandro was. After Jela's death, you should have enough angels to kill everyone.
2. Find the Alliance of Angels, MoD, and AoD somewhere and exchange them for the book of air.