Blackbeard is a direct offspring of Davy Jones's lineage and to this day neither Imu nor Gorosei have dared to try to eliminate him.
Another reason why Imu targeted with the posters too. It's all adding up. Along why Saturn said his bloodline was special.
Blackbeard has a "strange body", can eat more than 1 fruit, may not be able to sleep at all, has insane durability/pain tolerance, the "most evil fruit" in existence that seems to be sentient and a secret mythical zoan blatantly and thus most likely a god level fruit, permanently scarred Shanks a long time ago, was referred to as multiple people randomly by Zoro and Luffy as they sensed something in him that others couldn't sense.....What else?
Blackbeard is the most fascinating anomaly and people who think he's not gonna be the final villain after his actions in Impel Down and Marineford especially, over 20 years of buildup now and being named after one of the famous and important pirates in history and he's still making huge waves LITERALLY with not one but TWO devil fruits and inevitably a 3rd one later down the line, probably Imu's too after he kills Imu later?
And someone tried to explain to me that Imu is "not scared of Xebec", when Xebec casually strolled into the most secure, important place in the entire world, with the MOST powerful figure in the world in every sense of the word and also most elusive, secretive to the point the absolute majority of the world isn't aware of their existence and the truth and Imu here is also destroying Blackbeard's poster specifically?! The son of Xebec and descendant of Davy Jones himself now too?! LMAO.
So I wonder if Marshall is the name of Blackbeard's mother's family or just a fake name like Rocks seems to be? Imma read the spoilers again and try to take this in properly and get facts straight, this is too much to take in and process.