Because there are only four distinctive levels in the Marvel Universe Online, leveling is broken out based on a characters offensive and defensive powers. Every individual technique can be leveled independently through skill points gained through use or training, but a character isn’t considered “leveled” until both primary offensive and defensive powers have reached a certain skill level. This adds even more variety in the way you development of your character and allows you to adapt your character to the changing landscape of the enemies you face.

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Hero (Villain)

As a hero, your ability allows you to easily overcome 5 non-powered minions or three powered minions.  It would take two fully powered and trained heroes to defeat a fully powered and trained super villain.  A hero takes it to the streets protecting citizens neighborhood by neighborhood.

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Superhero (Super Villain)

As a superhero, you can easily defeat 12 non-powered minions or 5 powered minions.  It would take three fully powered and trained superheroes to defeat a single, fully powered and trained scourge.  You are the defender of the city and an icon of the people.

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Paragon (Scourge)

As a paragon, you can easily defeat 20 non-powered minions (usually the entire room) and 10 powered minions.  It would take 8 fully powered and trained paragons to stand against a single Cosmic.  You are a paragon, called upon to stop a hurtling asteroid or invading alien force. The world depends on you.

Image: Marvel Wiki

Cosmic

A fleeting level of power, cosmic is the pinnacle of power, but to no mortal man, alien, or demigod can hold it for long.  Cosmic power gives you the ability accesses all the possible combinations of powers within your origins as well as powers specified by the mission or object of empowerment that granted you cosmic-level abilities.  Reaching cosmic level will be temporary, but may leave the character with residual boosts to stats that fade over time.