This is our proprietary skill rating calculation. This has nothing to do with official game ranking or MMR.
The purpose is to show player skill levels relative to other players, not estimate MMR.
PASSIVE - Melee Basic Attacks decreases enemy Physical protections by 7, and increase your physical protection by 5 for 3s (max. 2 Stacks).
PASSIVE - Every fourth Basic Attack triggers a chain lightning, damaging the target and up to 4 nearby enemies for 15 damage +60% of your total Basic Attack Power.