Best coven for killing Gold Bittern

[Zanoss]

Hello, I'm in the post game dungeon and I was wondering, what is the best coven for killing the Gold Bittern ? I know there is a coven that can allow you to kill the Gold Bittern in one hit but I have no idea where I could get it, anyone know please ?

[spoilerspree]

Mysterious pact from Witch petition got that insta kill ring metal donum
100 Princess pact got pure Blunt damage to all enemies donum

[Plutia]

The Mysterious Coven has Tittilating Terror which does blunt damage to all enemies.

[Zanoss]

Thanks ! Indeed it work well. Now, I just have to find some good xp coven x)