The big blood eidolon is hiding beside the stone pillar in the depth of the secret cave. The stone pillar emenates red light. There is a Blood Charm that you can use to make the big blood eidolon appear. Then you can kill it. Thus the left blood eidolons would be afraid of you and leave you far away.
— Buddhist Novice Ming
The big blood eidolon is hiding beside the stone pillar in the depth of the secret cave. Use the Blood Charm to make it go out of there and then kill it.
Watch the Blood Charm carefully and don't lose it.
Is there the big blood eidolon in the secret cave? It should be just near a stone pillar. The pillar emanates red light.
Just as expected, it is the big blood eidolon that made trouble.