Mike saved Pierce few times before after the incident that party beach goers gone wrong during their pagent event it was aweful till changes are starting into less human as possible embracing the new imortality with their new lives as possible still Pierce recognized him as his son now a mermaid he knew his heart his son was there the recognition by scent in order to control the unstable dark magic surrounding them. Even heroes doesnt wear capes after they saved their former fathers the newly formed breeding mermen of the future.

Your world, my world. What's the difference?