When he's well out of earshot: "Do you remember that paper Wen Qing did, before the war, it might even exist already I'm not sure, about the theoretical possibility of golden core transfer?" 

"When the Wens attacked Lotus Pier, Wen Qing helped us get out. And she--I begged her to. Jiang Cheng didn't know. I told him that I knew where Baoshan Sanren's mountain was and that if he went up blindfolded and said he was me, that he was Cangse Sanren's son, that she could restore his golden core. I couldn't let him find out. You can be angry with me for this but he didn't have any idea." 

"Wei Ying."

He is angry, he's angry at Wei Ying and Jiang Cheng and Wen Qing and most of all himself for not realizing -

And Wei Ying had been all alone, the world hating him for making a sacrifice that no one else would be strong enough to make. Lan Wangji had been angry with him. Confused, and scared, but angry. And Wei Ying hadn't told him. Hadn't trusted him, maybe, but had Lan Wangji ever shown himself to be worthy of Wei Ying's trust?

He is so angry that he cannot breathe. He is horrified.

"Did it hurt?"

He bites his lip and looks away. 

"It was years ago, Lan Zhan. And now we're in the past and I even have my golden core back, so it's not that big a deal." 

"It'll be different this time, this can't go wrong the same way, Wen Zhuliu is already dead." 

That's both true and objectively great news, but it doesn't make Wangji feel any better right now. He clings to his Wei Ying and cries quietly into his neck.

"I love you, Lan Zhan. I--nothing like this is ever going to happen again but if it did I'd tell you this time, I promise," Wei Ying says quietly, hugging back as hard as he can. 

"Mn."

C l i n g

"I love you. I love you so much. I'm not going anywhere, Lan Zhan, I'm okay, I'm right here." 

He on no level deserves Lan Zhan, does he ever do anything but hurt him??? But Lan Zhan is definitely not going to let go no matter what he says so it doesn't really matter if he deserves him or not. 

That is correct, and it's good that Wei Ying knows it. "I love you. I will do better."

"I love you. I--I can't promise I won't ever use demonic cultivation again, after this is over, but--I'm not planning to, I'm going to pick Suibian back up again, and--I won't lose control again, I won't do this long enough, it won't have a chance to happen." 

Squeeze. Wei Ying had said he wouldn't lose control last time, but Lan Wangji doesn't want to fight about it. And - he trusts him. This time will be better, he'll make sure that it is better.

"I love you. If you lost control a thousand times I would love you."

Last time he said that and then continued to use demonic cultivation indefinitely. This time he's saying he'll stop! It's super different. 

"I really don't deserve you. I don't know how I'm lucky enough that you don't care but I never want to take it for granted."

"I failed you."

"You never stopped trying to save me. It's not your fault I made myself impossible to save."

"In your timeline, I succeeded. But I left you. I killed you."

"You didn't succeed, Lan Zhan. The only reason I haven't killed myself at any point in the past four years is that A-Yuan needed me."

Sounds Like A Success To Him

"But he had you. You lived." Wangji loves A-Yuan with all his heart, but he's under no illusions about being a better parent than Wei Ying.

"We couldn't leave the Burial Mounds, Lan Zhan. Not ever. I destroyed the besiegers, they were too terrified of me to try again, but only as long as none of us ever poked our noses out. A-Yuan deserved better than that." 

"He deserved a parent who could play with him." Who could talk and love easily, who could show him to laugh freely, who could go outside with him...

"I keep trying not to think about it. The fact that in this timeline A-Yuan's birth parents would still be alive. That making everything right means he'll never be ours."

He knows.

"It feels evil to think that - maybe... I am ashamed."