Board Thread:DC's Legends of Tomorrow discussions/@comment-807326-20181023024756/@comment-27700324-20181027051243

None. Riverdale and that whole Archie universe is actually connected to the Marvel universe despite being closer to the WB studios. They made a crossover with Punisher in an Archie comic back in the day. Despite not being a fan of that Archie world, i just got that crossover cause i like Punisher. So yeah, they are more likely to cross over with Netflix's Punisher than CW's Supergirl. Sometimes actors from other shows just like to hang on sets man.

Also i personally don't recommend Constantine. I just feel while the show had a creepy horror element and a good bit of talent with Matt Ryan as Constantine, the rest of it was never well fleshed out or done well. I would say just watch it for more Matt Ryan though.