Card Rulings talk:The Wicked Avatar

Is The Wicked Avatar immune to reduce-atk effect
it's always 100 more ATK than the higest monster on the field. so is that mean it's immune to "reduce ATK" effect?

for example, if the wicked avatar kill the Slate Warrior. since the slate warrior reduces 500 ATK and the DEF point to whatever the monster destroys him, would the avatar still have 100 more ATK than the highest monster on the field?