Calvin - Blood - Cianna
0 - 0 - Leader
0 - 0 - Shayd

0r,

0 - 0 - Cianna
Calvin - Blood - Main
0 - 0 - Shayd

Both of these work well, but the first seems to work better for the 1,250,000,000 Baal and Cerb Banish Bosses.
Make sure your highest Spirit is on Cianna. If you do not have a LB spirit for Calvin, then you need 90 or less moral Calvin to time his Moral Breaker hit correctly. I use a level 5 Rightousness, but you can use any morale rune that displays 90 or less Morale (Including a +15 Morale Saint if your hero has one.)

Banish formations are sometimes held closely secret by some people, I have noticed. Share the info and we can get the larger bosses quicker, as everyone will dish out more damage.