Xiao Li personality traits:

Willing to bend the rules if he thinks it's for the greater good. Believing the time trio over what happened with lu guang's stabbing and actively getting him moved to the unopened hospital and cxs and ql's suspect status delayed. Involving them in the investigation at all honestly.

Emotions blind him to objective reality. See: how he thought Qian Jin was an amazing officer and upstanding citizen until his wife died despite us now knowing QJ's moral slippage was occurring long before then. Thinking that Qian Jin must have changed because the Qian Jin he "knew" wouldn't have done these things.

Optimistic to a fault. Added to the previous point. Asked Qian Jin if he wanted to get his injuries checked out at the station when Qian Jin wanted nothing less. Trying the photo shop in the first place based off internet rumours on the off chance they could help with his case.

Sense of "justice" more a sense of guilt. Most of his s2 actions are fuelled by his need to fix things. He even admits that he was never the one who was an amazingly motivated police officer and he always saw that as Qian Jin's role. The difference here is that Xiao Li suddenly has personal stakes. The broad concept of justice is very different from seeing people's individual stories. An operation he ran resulted in someone getting stabbed so he tried to get Lu Guang safe and ran precautions that verged on paranoid (such as not informing his fellow officers about the powers). Chen Bin dies, so he insists he'll make it up for him and then resign. Wang Juan's fate is up in the air but is another instance where he screwed up because he was impulsive and chose to chase down Li Tianchen. And yet he keeps going regardless. He thinks that he can fix this if he just keeps going without necessarily learning the lessons he needs to succeed at that.

He's a shiguang mirror in one character. His Cheng Xiaoshi traits are much more obvious, of course. He's almost a bad end Cheng Xiaoshi in many ways. A Cheng Xiaoshi who never learnt. But his failure to properly communicate things to the people he's meant to be working alongside in case they screw it up is such a ridiculously Lu Guang trait it can't be ignored.