Black Strange, True God of Fate

Doctor Strange was clearly a man of action. He did what he said. After mastering the spell in the fastest way possible, he directly summoned a gigantic octopus monster through a magic circle. Yet this octopus monster was unexpectedly powerful. Not only did Doctor Strange fail to absorb it, but he was brutally beaten by it instead. Fortunately, he reacted quickly and was skilled enough to escape its tentacle play. The librarian Oben warned him that the power of mystical creatures was not suitable for humans. What was obsession?