Balanced alignment?

These should be quests with balanced servants

You can find a list of them here: https://grandorder.gamepress.gg/prisma-codes-mission-enemy-locations

Just click on Balanced Servant, and it will show you all the locations where you can find one, as well as the unlocking conditions for said locations.

*Edit* or just use the list that @tlas posted just now. But the link that I gave you will be handy if you have any similar questions in the future.