Very similar to the plot to Dandadan, but to be fair, it's not a difficult concept to come up with. It's similar to Fantasy vs Sci-Fi, but with the supernatural instead of magic. Even Marvel and DC have done similar things with magic / supernatural heroes vs. various villains including Aliens. Justice League Dark, and then that one Avengers team led by Doctor Strange whose name I forget.
What sets Dandadan apart is how well it does the Aliens vs Supernatural tale and how organic it feels, along with how innovatively they do it with incredible pacing and tight character development that's very emotional.
Good idea with great execution. Many good or even great ideas fail because of how they're implemented.