The MC reaches immortality by creating the 2d world, thus acceding the heavens as an immortal. However, in order to finalize it, he must first complete a mission. He gets tricked into taking on a near impossible mission: saving the ML in many different worlds. No one else has managed to even complete the first world. The stubborn and determined MC somehow manages to survive the multiple worlds, helping the ML with whatever issues he has in each world.
ML is pretty possessive but it has some really fluffy sweet moments too. Lots of flashbacks/ childhood connections/ recalling prev world.
World 1: ceo/ mafia (fully covered in ch 74–)
World 2: DID, cross dresser/cry bby—housemates
World 3: celebrity/ famous actor with insomnia
World 4: wuxia/ ancient China martial arts
Reminds me a bit of cheating men must die but without the help of a system.
100 Ways to Heal a Psychopath