2 suggestions: A really strong thing to bring against scarecrow is any shield. He is incredibly weak to parries. Getting used to parrying things will also be good practice for later bcs. If you use something like panchaku that hits a ton of times I would highly suggest the combo mutation. The damage that it would provide, especially in a boss fight is far beyond something like no mercy.
2 suggestions:
A really strong thing to bring against scarecrow is any shield. He is incredibly weak to parries. Getting used to parrying things will also be good practice for later bcs.
If you use something like panchaku that hits a ton of times I would highly suggest the combo mutation. The damage that it would provide, especially in a boss fight is far beyond something like no mercy.