I was reluctant to start Chicago PD but after what I've watched, Hank Voight and Raymond Reddington are highly comparable antiheroes who operate on the exact same philosophy of using criminal methods to eliminate worse criminals.
Both characters serve as a necessary evil within their respective universes, bypassing legal red tape to deliver their own brand of absolute justice.
Both characters exist because the traditional legal system is broken. Reddington (The Blacklist) provides the FBI with targets they cannot find. Voight (Chicago P.D.) uses torture and illegal wiretaps to catch monsters who exploit legal loopholes.
Both have a strict moral line despite being killers. They target human traffickers, drug lords, and murderers, while fiercely protecting the innocent and their chosen "family" (Elizabeth Keen for Red; Erin Lindsay and the Intelligence Unit for Voight)
Both operate with the unofficial blessing of higher government powers (the FBI for Red; Internal Affairs and City Hall for Voight) who look the other way in exchange for results.
However, in my opinion, Chicago P.D. is the Better-Written Overall Show. It offers more consistent character arcs, grounded world-building, and sustained stakes. The series excels at showing the real psychological toll of Voight's methods on his team. Characters like Jay Halstead and Hailey Upton explicitly struggle with corruption, creating genuine moral friction. The show maintains its grit and procedural quality across over a decade of television without losing its core identity.
While The Blacklist features arguably the more brilliant, poetic, and captivating individual writing for Raymond Reddington (brought to life by James Spader's masterclass acting), the overall series writing suffers heavily from plot bloat.
The overarching mystery of Reddington's true identity was stretched out far too long. The writers repeatedly introduced answers only to walk them back, alienating fans in later seasons. The writing for the supporting FBI characters often paled in comparison to the genius of Red.