BS2 SL1 DLC3 Boss 1

Done without leveling up, taking any stat-up souls, or going into Chaos Dungeon. Also this was done on Difficulty 9 by accident. The difficulty was changed to 0 after realizing this. Every subsequent boss fight is therefore done on difficulty 0 unless specified otherwise.
Covenant is Margaret
1st Turn: Switch to the Anchor and cast INDIGNATION. Then switch to Sword of Giants and use HAMMER. Then switch to Wand of R'lyeh and cast SPIRITUAL UNITY. End the turn by switching to Wand of Creation and casting GHOSTFIRE and ABSOLUTE PRECISION. Boss will do something that doesn't damage
2nd turn: Switch to Sword of the Giants and use HAMMER. Switch to Wand of R'lyeh and use SPIRITUAL UNITY. Switch to Jubjub's bow and cast MAD BIRD'S SHRIEK. Switch to Wand of Creation and use MEAT SHIELD SPELL. End turn by casting KING'S ORDER. Enemy attacks. Hope to RNG that it hits your meatshield.
3rd turn: Switch to Sword of Giants and use HAMMER. Switch to Jabberwock's Scythe and use SOUL BREAK and GHOSTFIRE. Switch to Wand of R'lyeh and use SPIRITUAL UNITY. Then switch to Wand of Creation and use DISPEL (Gets rid of enemy Requiem and Evade). Boss attacks. Hope again that it hits your meat shield
4th turn: Switch to Sword of Giants and use HAMMER. Switch to Kishingatana and use it's last skill four times. Boss will either charge special or attack you or your meatshield. Hope that he charges special
5th turn: Switch to Jabber's Scythe and use the skill that does 5% of its HP and 3% of its HP. You probably can't use that weapon's best skill because last turn used up too much MP. Switch to Wand of Creation and use GHOSTFIRE, ACID RAIN, and that one spell that does 3% of an enemy's health. The Penultimate spell will kill the enemy, but they have an 80% chance to revive. Hope they stay dead. If not, the last spell will also kill the boss but again, it has an 80% chance to survive.