Most powerful mutant in marvel database?

Dark Phoenix is supposed to be the most feared and strong mutant in Marvel. To say that Magneto isn't the most powerful so confidently is kind of stupid. Magneto is a cl 5 mutant,the strongest kind. If you go with the science of his powers he could destroy earth and any planet with an atmosphere instantly.Blood in most heroes contains mineral properties and metal elements, Magneto could kill anyone theoretically,it was also done in the comics where Magneto caused her an intense stroke that later lead her to her death.Though the comics would never do this because he would be far too powerful,they imply that Dark Phoenix is the most powerful.