He looks like he traveled back in time to tell himself to stick to VHS porn.
Could it be that Herman's blood pact with the Prince of Darkness entails a forever-walk among the living damned? Perhaps that's the in-canon explanation, but as Reubens later admitted, the true secret is simply that they used computers to de-age the star, not unlike they did with Michael Douglas at the beginning of Ant-Man or that adorable li'l Robert Downey Jr. in Civil War.
Marvel's next project is a shot-for-shot remake of Wonder Boys.
We've come a long way since the anus-clenching horror of Tron: Legacy's CGI Jeff Bridges -- to the point that movies are applying "beauty work" so readily that we no longer notice it's happening. And it is happening. All the damn time. Here are some before and after samples from Vitality Visual Effects, one of the many CGI companies specializing in making actors and actresses look like vampire clones of themselves: