Giyuu's subconscious.
The kitsune helped Giyuu up and invited him to drink tea with him.
Giyuu accepted the offer.
After drinking is matcha, Giyuu asked the kitsune why he was here.
Kitsune: Well, your body is currently undergoing changes.
Giyuu nodded seeing that he had awakened his kitsune side.
But Giyuu wondered why his conscience was here!?
Kitsune: So I can answer your question. But especially with my relationship with Muzan and me.
Giyuu nodded and the kitsune summoned a ball and said: Touch it and you will have all the answers to your questions.
Without wasting a second Giyuu touched the ball and disappeared, gasping in surprise.
The kitsune sighed and continued drinking his tea.
I leave you the rest of my reincarnation.
To be continued