Hi. I have one question.
My friend (lv 150+) lost against somebody at lv 100+. So my question is if both of the player have for example, angelion, is the higher hero rank dealt more damage than lower one? Or it is the same for both?
Im sorry for my bad english. Have a good day!
It is the same for both, perhaps the opposite attacked with bloody rage and that is why the damage was greater
So both hero rank have nothing to do with the damage? I thought the higher your hero rank the easier for you to defeat your opponent
No
My hero rank is 84 but since I was 72 I was able to beat players over 100
The only PvP advantage to having a higher hero rank is having 206 total cost available. That caps at level 100.
As already mentioned the monsters are not stronger in anyway the higher the hero rank.
Wish it was like this, my monsters would 1 shot everything 
In PvP you are playing against humans and sometimes you run into someone that is better than you. Also your opponent might hard counter your main strategy and in that case it will be close to impossible to win. Hero rank only influences maximum team cost up to a certain level.
Thanks for your respond!