Both dramas have a main character that is a apecial agent who secretly works for a government but does not let their romantic partner know.

Both shows have an older ML who tries to protect the FL from harm due to the FL's evil miasma. FL is kind and innocent but gets harmed because the immortals do not believe her. FL goes through multiple lifetimes and her experience changes her personality.

Both dramas are about immortals falling in love, ML tries to protect FL and often gets himself injured in the process. ML breaks rules for FL.

Both MLs are deadly powerful beings but must obey the FL's commands as they are bounded by a spell related to their past life.

Both dramas are about characters entering a virtual reality game world that blends with real life and involves real life and death situations.

The dramas have similar time travel principles - they use single world rather than parallel worlds, meaning when something gets changed in the past, it causes a ripple effect in present time rather than creating a new, diverging timeline. Because of this, the dramas reminded me of each other a lot. The romance and angst is also at a similar level.

Both dramas:
- Are xianxia romance dramas
- Have a ML who is a demon king
- Have a FL who was created in the heavenly realm but falls for the demon king
- Have FLs redeem and change the nature of the ML through love
- Have FLs risk going through a life or death situation to stay with the ML
- Have a love-hate relationship between the leads caused by inability to express their true feelings

Both dramas:
- are about comic book characters
- have characters becoming self-aware and trying to alter the comic's plot
- have leads who fall in love despite the comic's plot not originally intending them to
- have a FL who is not supposed to be the lead of the comic
- have a ML who is originally just a side character of the comic but becomes more integral after tampering with the plot
- have a smart FL who tries to dissect what is going to happen next

- Both are xianxia romance dramas
- Both involve the male lead misunderstanding the female lead and hurting her
- Both have a lot of angst
- Both have the main couple separating and reuniting

- Both are xianxia dramas
- Both involve misunderstandings that bring the main couple apart
- Strong male lead
- Both are angsty and tragic
- Both have the characters changing into other identities

The plot synopsis is nearly identical:
- Both have a fox demon male lead trying to cultivate their powers through a bead
- Both involve the female lead accidentally consuming the bead
- Both male leads end up living with the female lead to try and get the bead back
- Both involve the female lead potentially dying from the bead if it gets removed/stays in her body for too long

It's also about a cat turning into human and falling in love with their owner, just that in I'm a Pet At Dali Temple, the FL is the cat, while in Welcome, the ML is the cat.