in “Incense Burner,” wwx easily defeats 15yo and 18yo lwj. In this short, wwx tells a 15yo lwj that he is “7 years from the future” and later again states that he’s 20-something, so we see this takes place just after the story ends. however, we also read in the short regarding wwx vs. 18-yo lwj:

“Right now, in spite of his level of cultivation being much higher than Lan WangJi’s he was still unable to resist.”

So, seeing as wwx and lwj were both ~18yo in the Xuanwu cave and wwx loses his core soon thereafter, assuming that wwx and lwj were equals before wwx lost his core, we determine that wwx in “Incense Burner” already has cultivation level much higher than when he was 18 in his old body (right before he lost the ability to cultivate spiritual energy)

In conclusion: wwx is a badass who gets his golden core back and surpasses his previous level of cultivation before he originally lost his core in <1 year after resurrection.

like he’s heir to one of the four most prominent cultivation sects (and thus rich af), been basically praised by everyone his whole life, probably doesnt even have any concept of being poor/hungry/homeless/dispossessed until everything goes down w WWX and the Wens...

his moral compass was completely dictated by the rules on his wall, questioning authority was unthinkable. and sure, he probably started to wonder a little bit, after personally witnessing how he and WWX got the same grades and were matched in cultivation, but while he was the peerless paragon of all disciples, WWX was just the son of a servant, so lucky to be adopted, and did you hear how often Madame Yu beats him? but he never really spoke up. he didn’t publically defend WWX when WWX took in the Wens (because, again, what’s poor? what’s starving? but WWX had fought stray dogs on the streets for scraps since he was 4) he didn’t defend WWX on Pheonix Mountain. it’s only after Nightlesss City, in that cave with a half-dead WWX in his lap and 30 Lan elders surging in, that he really had to make a definitive choice: obey, or do what he thought was right?

This has probably been discussed a decent amount before, but 如兰, or orchid-like, connotes elegance, gentleman-like demeanor, etc., which are all traits that WWX associates with LWJ. The lan character here, 兰, is pronounced exactly the same as the GusuLan name, 蓝.

Meanwhile 思追 literally means “to think of” (思) and “to chase” (追). Together, it denotes longing. The name derives from a line of poetry (by MXTX, I believe): 

思君不可追，念君何时归

i think of you, but i cannot follow you/ i ask for when you will return

Thirteen years of grief, yearning, and waiting on LWJ’s part is encapsulated in the Lan SiZhui’s name.

As a bonus: SiZhui’s birth name given by LWJ, Lan Yuan (蓝愿), includes the character 愿, which has often been translated as hope. Though I’m by no means fluent in Chinese, it’s also interesting for me to notice other connotations of 愿 as a native Chinese speaker. For instance, consider the terms that can be formed with 愿:

愿意： want to/be willing to

愿望： desire/dream

心愿： wish/heart’s desire

不忘 (Won’t Forget) by Wang Yibo 王一博  陈情令 The Untamed Lan Wangji OST  direct translation here

云深夜微凉  on a cool night in the Cloud Recesses,

皎月清风拂心绕 with heart touched by bright moon and gentle breeze,

一人对雪望 a lone figure gazes toward the snow

望尽前尘事过往 reminiscing upon past deeds