Someone can explain the difference between the Hero damage and attack damage please?
While not an expert and I could be wrong, I think "attack damage" refers to damage from auto attack only. I think "hero damage" includes damage from all sources produced by the hero including skill damage, divine and attack damage.
A hero's final ATK value is the result of their Base ATK, added and or multiplied by what ATK buffs you've applied. A hero's base ATK is fixed and depends on the hero's level. For example, a level 1 Savage Chief has a base ATK of 540, which increases to 550 at level 2 and so on until level 200, where his base ATK reaches a maximum of 5360. Every hero has a different minimum and maximum base ATK and HP.
Another point worth mentioning is that ATK multipliers are accounted for before linear ATK buffs are added. That is to say, at Taurus evolution, where Savage Chief receives 300+45% ATK, he receives the +45% buff before the +300 buff. If he has no other buffs active (and we assume he is level 50 - where he has a base ATK of 1360) then his final ATK value will be:
The formula for ATK can more generally be written as:
(You can check this formula with any hero for HP or ATK)
I agree with this explanation of base attack and multipliers to base attack. It is also one of the reasons why I prefer Blessed Weapons as a Talent. But, I am not sure that is the same as the phrase 'attack damage" as in the glyph described above.
It is all too true that IGG leaves a lot to be desired when it comes to descriptions of their effects in game. They are often very unclear.
My concern is that IGG uses the Talent called "Battle Fever" to do exactly what I think you describe in your description of base attack. Battle Fever says: "Increases Hero ATK by 8%". We all know that they mean an increase to "base attack."
So, because they already have wording that they could have used and did not, I would think they could mean something else when they say "Attack Damage +50%". If they meant it to be an increase to base attack why not use "Increases Hero ATK by 50%".
Now "Blessed Weapons" does say "Increases Hero DMG by 8%" and that is the same function of the top part of the "Butcher" glyph which uses the phrase "Hero DMG +25%". They did not use the same language as before which might suggest a change in wording to a bunch of glyphs with wording describing similar functionality already in game.
So, you very well could be right. I have not tested the glyph at all. I do not know anyone who has. But, maybe it would be worth trying to figure out by someone more motivated than me.
As an edit, I looked at other glyphs like Riposte which deals with damage reflect. They seem to allow for two different damage reflect possibilities: Attack DMG Reflect and Skill DMG Reflect. This supports my original theory that Attack DMG is auto attack. Skill DMG probably includes divine and active skill damage. So, absent testing to the contrary, I think that the glyph in question using the words "Attack Damage +50%" boosts auto attack and not all attacks using base attack.
As Kuzog said, attack damage increases normal attacks damage, while hero dmg both, normal and skill attacks. Didn't test atk dmg, but it's very probable it increases total normal atk value after including hero dmg as skill dmg does.