This is also my question but based on the season 2 anime, it's unlikely that he can be normal human again since the gods place more blessings onto him and have their personal interest(which is the offerings) in the mc. Its impossible for them to ignore or just shrug the situation when the mc will die.
Spoiler: The higher god gave him a life span same with higher elf. He will live very long.
The issue about having sex slave is not true base on the novel the God grant him a long life span in exchange with an interesting adventure life instead of a love life. Even tho mc would prefer a love life over a long life span.
The God is in our side hehe. ╮(￣▽￣)╭
The author is disappointing at some point because he/she made the mc divert his main goal to wanting to have a love life rather traveling around the world since the first release of this manga.
will the mc live for long and be with his familiars until the day he die? or will he be immortal together with his familiars?