green goblin

Hi,

I can't find the original post of green goblin spotlight and i don't know if anyone asked that before or not, but i don't fully understand how his regen works.
In his abilities it says: "While Green Goblin has more Madness than Cunning, or the two are equal, he passively Regenerates 60% of damage taken from Basic Attacks and opponents deal 30% less damage on Special Attacks"
how is this 60% works?
is he regen 60% of each single hit all at once, similar to ultron sig ability when he regen back the damage from energy hit?
is he regen 60% at once of the total damage taken since the fight start?
is he regen 60% but not at once, X% per tick from the damage taken since he entered his regen mode?

i tried to duel a Green Goblin and the moment I saw him regen health i stopped hitting him but he keep regen.
is it a bug or his regen works differently?

Thanks