Honkai Impact 3rd: Sinner's Elegy

The man hummed a tune, oblivious to everything around him. Raiden Mei stood off to one side, watching him. She waited until he finished humming before speaking. “You still haven’t told me why you’re in the Elysian Realm. You’re neither a Flame-Chaser nor a caretaker, so why did you leave behind a memory?”

The man chuckled softly and looked at Mei. “You’re a lot like Mei. Has Kevin ever told you that?”

“Answer me.” Mei’s expression remained blank, but faint arcs of lightning appeared around her.

“...First, you need to know who I am, don’t you?” The man turned to face her. Mei froze for a moment. She really didn’t know who he was, but many people had mentioned him before.

Even the stone-faced Kevin had warned her, “You’d better not go see him. I can’t be sure when he last synchronized his memories. If you’re unlucky...”

“You two haven’t met in twenty thousand years?” Mei interrupted him. Kevin turned away in silence and said no more.

Elysia, on the other hand, had been all for it. According to her, though, the man was a little... um, socially anxious?

Coming back to herself, Mei looked at the black-haired man smiling at her and asked in confusion, “Aren’t you Xie Wan?” The man... or rather, Xie Wan, was still smiling. “So you still don’t know, huh? You’ll find out who I am as we continue our journey.” Mei let the arcs of electricity around her fade, but she was still puzzled. “Why did Kevin advise me not to come see you?” Xie Wan pulled a novel from who knew where and held it out toward Mei. “Want to read it together?”

Mei sighed helplessly and went over to stand beside him, lowering her head to look at the cover.

The title on it read:

Honkai: Sinner's Elegy