After Odin died in the battle against Surtur, Asgard was left without a ruler. Thus, Thor became the next ruler, it is at this point he also obtained the Odin-Force for himself (here it was referred as Thor-Force) This version was even more powerful. King Thor was powerful enough to even destroy the tree of life, which holds the 9 realms together!
The devourer of the worlds (now life-bringer) needs no introduction, his powers come from the ‘power cosmic’ and he is extremely strong and all knowledgeable. He is the oldest being in the marvel universe. It is almost impossible to defeat him once fed, but he can be defeated if starving. With the vast cosmic knowledge he has, if Thanos faces him then he would get destroyed in seconds. In fact, the God of Marvel comics Stan Lee also said that Galactus is certainly the most powerful character in the Marvel universe.