Rather dismally, Oblivion is the personification of the void, collapse or death of the universe and he was created just after the universe itself was. Obviously, as a result of his nature, he possesses the power to destroy universes but, just to put exactly how powerful he is in to perspective, a mere aspect of Oblivion, Amatsu-Mikaboshi (think of Amatsu-Mikaboshi as the Silver Surfer to Oblivion's Galactus), was able to destroy almost all of the multiverse. His powers are cosmic in nature and they are very similar to so many others on this list, though his are dark and he will opt to use them for destructive purposes more than most. He can fly and traverse dimensions, can manipulate probability and reality itself, can alter his size, manipulate the souls of living beings and can manipulate and fire various kinds of energy for the purposes of destruction. He is one of the more sinister-looking entities of the Marvel cosmic roster and, due to the nature of his character, that really should come as no surprise.
13 & 12. Mistress Love & Master Hate
Given that this pair are exact opposites of each other and are regularly uttered in the same breath and seen together, there is literally no way of separating them - they each play host to the exact same amounts of power, just of entirely different concepts. Mistress Love is a divine goddess who represents all the love in the universe. She is worshipped by the Amaru people and in return she has given them paranormal abilities - in much the same way that Galactus gives power to his Heralds. She can control all the love in the universe and, as such, can make people love things and each other and, although she can appear however she wants, appears as an attractive female. However, when the time requires it, she can be just as devastating as other cosmic entities when it comes to her attack - with the ability to fire powerful cosmic energy bolts. That said, when she has the power to make almost any being fall in love with her, what more weapons do you need? Master Hate is the exact opposite and is the embodiment of all the hate in the universe. He possesses incalculable strength, incalculable durability, incalculable speed and numerous other incalculable traits and is more than capable of handling himself in a fight - as you would expect of someone who is inherently full of pure hatred and cosmic power. He can make anyone hate anyone else and, just like Mistress Love could do with her power over love, he could use that in his favour to make beings attack each other and avoid having to lift a finger in battle himself.
