An' ya realize yer goin' toe-to-toe with a walkin' earthquake. It's when ya come back that ya feel the pain. It's like he hits ya so damn hard ya actually leave yer own body. Simple fact bein' there ain't many around who can survive to tell the tale. “There ain't many around who can describe what it feels like to get hit by the Hulk. Thanos has powerful survivability, and has curbed the Silver Surfer’s attacks in the comic books, but depending on the conditions, the Silver Surfer could be capable of destroying Thanos. The Silver Surfer is capable of surviving a black hole, and it would be no great surprise if he survived an attack by Thanos. His detection abilities even let him see through time and into the future. He also has the power to detect entities light years away, making it difficult for sneak attacks. While not strictly immortal, the Silver Surfer is nearly indestructible and impervious to almost all attacks. Through this power, he has incalculable levels of strength that rivals even the most powerful of characters. The Silver Surfer has “the power cosmic”, which lets him alter the fabric and energy of the universe. Henceforth, Norrin became the Silver Surfer. Galactus agreed to Radd’s plea and transformed him into a herald to seek out other planets for Galactus to devour. At the last minute, Norrin Radd, a native of Zenn-La, appeared and pleaded for Galactus to spare his planet. Galactus, a powerful planet eater, was ready to consume the world Zenn-La. Thanos could have an opportunity to disrupt her, as the Phoenix Force operating through Jean is vulnerable to psychic and physical attacks, since Jean is a human and mortal. If the Phoenix Force mission or purpose was aligned with Jean in removing Thanos, it could be done. The entity itself is not easily controlled or told what to do. While the Phoenix Entity could destroy Thanos without much of a thought, Jean Grey would have a harder time. The Silver Surfer rated the Phoenix Entity as an extinction level threat, and the Marvel Wikia gives it the the maximum level rating for intelligence, strength, speed, durability, energy projection, and fighting skills. The Phoenix Force Entity is one of, if not the most, powerful and immortal beings in the entire Marvel Universe. It can make intergalactic flights through hyperspace and bend the universe onto itself to form black holes.
The Phoenix Force Entity can destroy and regrow the existence of the universe itself, as well as control the powers of life and death. As a hungry Phoenix, the being flew to a galaxy and simply devoured an entire star, which also killed billions of people in the stars vicinity. The Phoenix Force is an amazing entity that is a representation of the universal life force. Jean Grey is a powerful character in her own right, but when combined with the Phoenix Force, her powers are awesome and nearly unmatched.