Pluto has no heart.
Life and death are divided into two volumes: Chenghuan and Liluo. The Chenghuan scroll contains people who have no regrets and finally reincarnated with peace of mind. The Liluo volume contains people who are unwilling to drink Mengpo soup and walk across the Naihe Bridge.
Pluto went to see Nuwa for help, but Nuwa only told him one way.
Unless there is a soul that does not want to be reincarnated and is willing to stay in the underworld for life after life and never enter reincarnation, then when time erases the memory and the sediment in the heart is slowly filtered, the day this soul completely becomes a walking corpse, his heart will be clean and transparent.
Only then could Hades get a heart from that soul.
The opening really moved me, I cried to death