The deaths of both Shiki & Hiroki are that they were two adults torn down by society. Though for Shiki it was happening all throughout her life, while for Hiroki it happened after his wife left him and he fell to earth. Though it’s cool to see how the protagonists from each faction were able to bring them up in their own way. Shinoha with his kindness and Kiwami with his cruelty. Ignore how creepy it was that Shiki was crushing on a kid.
With that being said, I did not expect Gamute to be Kiwami’s son. It adds the question of who Gamute’s mother was since she abused him. Also curious about Gamute’s squad since Gamute is set on taking out both Kiwami & the ninjas.