FLASHBACK
"Do you know the Bootstrap paradox?"
The man crossed his hands and asked Arthur, who was looking back at him.
"No, what is it?"
"On earth, it's just a theoretical paradox of time travel that occurs when something sent back in time becomes trapped in an infinite loop of cause and effect. The origin of whatever is stuck cannot be determined so it's said to be uncaused or self-created. This applies to Dark Magic, for example. As you know, Zodiak received the black seed from the old you, who went back in time, and you got it from the fake corpse. Even if you trace it back to the first cycle, it'll still remain indiscernible."
"What are you trying to say exactly?" asked back the confused Arthur.