Is the animated series Constantine: The Legend Continues actually part of the Arrowverse? John Constantine is a cult comic character who first appeared in Swamp Thing before earning his own series with Hellblazer. John is a hard-boiled occult detective, who was famously visually based on Sting. Constantine might be a total cynic with a bad attitude, but despite his anti-hero nature he usually ends up doing the right thing - even when it comes at a personal cost.
Since the source material is fairly dark the road to a Constantine movie was a long one. Nic Cage was once attached before Keanu Reeves signed on, which proved very controversial among fans since the character became a dark-haired American instead of a blond-haired detective from Liverpool. The overall response to the 2005 movie was somewhat mixed upon release, but over time it's developed a passionate fanbase, with Reeves stating he's open to a potential sequel. In 2014 a Constantine TV series debuted on NBC with Matt Ryan playing the title role.
The series suffered from lukewarm ratings and the network restricted things like John's chain-smoking, but the show still won a following and everyone agreed Ryan was perfect casting. The series was cancelled after one season, but Ryan's Constantine later made a guest appearance on The CW's Arrow and later became a regular on Legends Of Tomorrow. In 2018 a TV special dubbed Constantine: The Legend Continues aired on the network, which consisted of an animated Constantine adventure.
Being that this animated special aired on The CW it felt somewhat safe to assume Constantine: The Legend Continues was following on from the continuity of both the NBC series and the Arrowverse, but this isn't the case. Firstly, it's important to clear up what the animated portion of Constantine: The Legend Continues is. It actually comes from Constantine: City Of Demons, which was originally made up of five short episodes that appeared on CW Seed in early 2018, while a feature-length movie with more footage was released on home video in late 2018. The Legend Continues aired shortly after and is made up of the first half of City Of Demons.
To finish things off, Constantine: City Of Demons was later broken up into two episodes on CW Seed, with the second episode consisting of the latter half of the movie version. All of which is a convoluted way of explaining that Constantine: The Legend Continues has nothing to do with the Arrowverse despite airing on The CW, with this version of the character hailing from the DC Animated Movie Universe, which he appears in the likes of Justice League Dark. The one constant between them all is Matt Ryan, which is always a good thing.