The fact that Ditko's heirs are fighting for this just shows how insane copyright law has become.

The entire point of copyright law is to protect authors from publishing houses so that successful authors are encouraged to produce more works.

Neither of the parties in this case are the original creator so there's no reason for either of them to hold copyrights. Only one of them is even considering making new content and, I would argue, Marvel is far more concerned with injecting IDPOL into existing properties and cashing in than creating new works or even maintaining the original works.

Fuck em both.