They are both adapted from Ikeido Jun novels and deal with fight for justice and against corruption in a working environment

Both of them are probably the best action-thriller-zombie Korean projects, and definitely among the best internationally! Both stories are more or less predictable and not too frightening or gory, but they were intense and suspenseful.
The acting and characters were great, the music well-fitted, the directing and cinematography superb.

Both are funny and entertaining comedy-action movies, with a wonderful chemistry between main leads. Both have Sung Dong Il in their cast. Highly recommended for a Sunday afternoon leisure time!

With almost the same main cast, "AWTG: Two Worlds" is actually the prequel of this movie. Both are focused on a "paragon's" trials in order for him to successfully reincarnate. Both have lots of CGIs and fight scenes, as well as some touching moments.

Both are medical dramas that are mainly focused on the medical aspect and power struggles, rather than romance.
Both dramas show the real human nature: from legality, hypocrisy, greed and ambition to morality, dignity, selflessness, common good and humanity.

Both are family dramas about a divorcee mother and a widowed father coming together and becoming one big family. Each family member have their own interesting story and their own obstacles to overcome.
Both dramas are heart-warming, with funny and light-angst moments, and entertaining.

Both dramas have and interesting and intriguing story, magnificent acting, as well as deep and growing characters, well-fitting music and beautiful cinematography.

Both dramas are about women who change their entire image with plastic surgery. Both are depicting the struggles of love and life that these women face, especially focusing on their learning how to slowly accept themselves, overcoming criticism using their own strength and value, and standing up to their fears and inner doubts.