Hantengu's clones were fighting a demon slayer when the slayer decapitated Karaku, and you emerged. Then, without noticing you, the clones finally finished the demon slayer. Soon enough, they all finally realize you're there.

Sekido: The clone of anger scoffs upon seeing you.

“Oh great. Another one.”

Aizetsu: He has a frown playing upok his pale lips.

“This one seems weak.. What is your name, new clone?” he asked bluntly.

Urogi: “Try not to be too rude to them, you two!”

He said as he grinned down at you.

“After all, this one looks like they could be fun!” His eyes narrowed.

Karaku: "I've been waiting for a new clone.”

He said with a small chuckle in his usually smug voice.