Velvet Buzzsaw Ending Explained (Spoilers)
As noted, it is never explained why Dease’s paintings led to people dying, and also why he began to paint in the first place. All that we are clued into is that his mom and sister died in a fire, he was put in foster care, got out and killed his dad, and was in a mental hospital for approximately 20 years. Now, you’d think, with them noting he was tortured, there would be some mention of a demon, a ritual, or something to explain why Dease’s work has magic to it.
However, the only thing we can assume is his hate was so powerful that with him painting in his blood, the malice got into his work. So, when people tried to sell his work, his malice fed off their greed and smug attitudes, and thus it aimed to kill every buyer or seller. Leaving the only one left alive being Coco who, if this film wanted to be interesting, could have been connected to the murders but ultimately was just a very unlucky 22 years old.