Like Mistress Love and Master Hate, there is literally no way to separate these two. Each possesses exactly the same amount of opposing types of power and you will always hear them discussed as a pair and they will often appear as a pair as well - indeed, they practically exist together at all times. Master Order is the embodiment of all things orderly. He tries to think of things rationally and maintain structure in the universe, whereas Lord Chaos is all about havoc and, essentially, destruction. As a result, they constantly talk to each other to strike up a balance, with Lord Chaos constantly asking Master Order questions that he tries to answer to his satisfaction (indeed, the pair created the entity known as the In-Betweener in order to maintain the balance of Order and Chaos in the universe). While they have no physical bodies, they appear as two giant faces (Master Order being a bald-headed man and Lord Chaos looking that little bit more monstrous), but they subconsciously maintain that perfect balance between order and chaos across the universe and were able to create a character almost powerful enough to sneak in to the top ten of this list, so they are clearly incredibly formidable.
7. Infinity
Infinity is an incredibly powerful cosmic entity who represents the infinite potential of existence. She is the sister of Eternity and, together, they have a responsibility to maintain the balance between life and death. Where Eternity represents all time in the universe, Infinity represents all space and of all the great cosmic powers she is the one who is seen the least often - though it is not known if she is intentionally reclusive or if it just a result of circumstance. As her name would suggest, Infinity possesses near limitless power and she most often manifests in female form, whereas her brother manifests as a male. Such is her power that she can easily best the likes of Galactus and galaxy-busting gods like Odin have used tiny fractions of her power to augment their own. She can wield vast cosmic energies for a wide variety of effects, including powerful energy manipulation, and she is almost omniscient and omnipresent.