I am looking for a horror novel that came out in the 80s,90s. its about a man that fights a demon. the parts that i remember are a group of archeologists uncover a cave where the demon used to live. the story switches to Africa where the demon now resides and its killing people. it does this by possesing the victim and luring them to its lair, it kills by inserting two tentacles in the eyes of the victims. This is the way the demon feeds. the main character of the book is taken to a village there to see a man who survived the demon. He survived because the demon sensed a tumor in his brain as it was inserting the tentacles, so it couldn't continue feeding. As a attempt to kill the demon fails, he flees to United States where it is protected by a cult. under hypnosis, it is found out that the main character of the story is a distant relative of a hero who fought the demon before,for this reason he is immune from possesion. thank you.