Board Thread:Theories and Rumors/@comment-28313176-20180914131834/@comment-36592086-20180919012734

Ninja72 wrote: No. The FSM died centuries before Battle Between Brothers. Moreover, it has been said multiple times that he made Wu and Garmadon swear that they would protect the Golden Weapons. I think he just died of old age, I mean he already looked old, when Wu and Garmadon were children, so him dying of old age is the most likely cause. Mmmm....

I think he's supposed to be portrayed as "immortal". Someone explained to me that when your invincible, you can't be killed, but you can die of old age, and immortality is the other way around.