It looks like the manhwa artist/studio didn't read the novel or tried to change the story by making the architect survive, maybe the author told them to just follow the original story and made MC state in this chapter that is most likely dead for good.
I don't remember the novel chapter word for word but I don't think there was any note of the architect using a proxy body from MC at the end of the double dungeon arc, bastrad just got killed when the dark heart didn't take control.
I'll forever find weird how the admin couldn't control the system he had built or used it on himself to grant level 1000 or something, big hole for me.