Guardian Angel Break-down (in General)

As I cannot find my answer in the wiki, and since I get contradicting advise while searching past threads, I hope there are people around who knows their GA.

Boring narcissistic justification: GA retaliation onto my familiar is the most dangerous thing for me to face and naturally I want to reduce it. DM is out of the question since without my AMF, spells like Decay and Magic Missile will whip me.

If the GA level is more than or equal to 2,5 times my damage, the opponent retaliates for about 60% of the dealt damage, this is clear to me. However.. what happens when it is less?

If I deal 1M damage onto a 1,5M GA.. is there a way to find out how big the retaliation is?
Will the actual damage returned be smaller/bigger or the same if I deal 2M damage onto that 1,5M GA?

I find that GA at around the same level as the damage being done returns around 30-50% of the damage dealt back.

1.5 mil GA will cover up to 600k worth of damage. So the retaliation will be a bit more than 360k. Even if you deal 2 mil instead of 1 mil damage the retaliation will still end up being about 370k max.

My GUESS:

At 2.5x it returns 60%, so at 1.25x it would be safe to assume it returns 30%? If the last one is true, then:
1mil Dam onto 1.5mil means 1.5x which would equal to 36% (360k returned).
2mil Dam onto 1.5mil means 0.75 which = 18% (360k returned)

That is considering that the returned percentage is linear depending on the damage.

Ah.. thanks for the clarification!

It thus seems like the electric familiar is the best one, with regards to GA backlash.

On a side note.. does 'innate armor' from Steel Skin help against GA?

Yes, EF is defiantly the best against GA. It is also the best against AMF. I would also assume that SS would protect from GA since all armor types do.