Azazel. Abilities include teleportation, absolute destruction, reality manipulation, space-time control, size increase, dimension control and finally, Retribution.
Katarina was always wondering why it never used some of its abilities and finally figured it out.
A good portion of its abilities were used to forge a single one - Retribution.
Honestly, after figuring it out, Katarina almost felt like laughing out loud.
Why? It was so broken to the point it was ridiculous.
For one, just a single one of its effects allowed it to shrug off almost all damage done to it under certain circumstances.
Damage immunity so long as it still had a single drop of mana left and it was being attacked by more than a two people.
And the ability to deal a certain amount of damage to a person depending on how many lives the person has taken.
The second was dependent on the difference in strength but damage would always be done regardless.