Both involve the prosecution, rampant corruption in the system, and political intrigue with the MC being a public prosecutor while seeking justice/truth. There is also the theme of justice and what it means. Both Antagonists also believe ends justify the means. (This is explored more in-depth in Strangers ) Both also give no focus to a romantic plotline.

BUT apart from these, the vibes are totally different. I enjoyed watching both but in different ways.

While Again My Life is more action thriller with wonderful action scenes and acting from Lee Min Gi, and is extremely entertaining, thrilling, and satisfying to watch. It is based on a fantasy of a second chance at life, where MC is blessed with multiple talents, lots of luck, and fateful encounters with the perfect people.

Strangers S1&2 is a more serious political drama thriller with more complex characters and a plot grounded in everyday nitty-gritty realism where MC suffers lots of losses and setbacks and is nowhere as charming and socially adept and lacks any of the social support the former (Again My Life MC )has. It is however a terrific watch and Cho Seung Woo's chemistry with Bae Donna (despite also being a non-romance drama, in Strangers you actually root for and ship the main leads more!) is a pleasure to see, the cast's acting and cinematography are also truly top-notch!

Not exactly alike but both 1)involve political intrigue/power play and carry a similar undercurrent of justice and what it means for a nation. Both consist of a few touching/emotional moments of men who truly want the best for the people 2)an underdog's pursuit of truth/justice with some loyal supporters by his side and 3)antagonists who believe the end justifies the means.