Honestly there's many things to it, first of all depending on the hero and your playstyle how u would want to play it, for example here Dracula he is like a lifesteal type of, so in general if u desire more lifesteal as much as possible then there's a rune which provide health regeneratation which will be helpful for Dracula to regen, but if someone is already satisfied with the lifesteal he gets from the cards he will according to his preference choose the rune set which will be suitable, if u feel u die easily, take some defense/hp rune if u want more attack to take attack boosting rune
Now another example, take a marksman, in general marksman needs attack speed, power and crits and lifesteal as well according to preference, now u set up the cards according to your desired needs but still feel the lack of some crits or lifesteal, then u fill it will runes take the desired runes to increase your power/attack speed/ lifesteal or even defence. It's all about gameplay experience, plsystyle and preference
First of fall see our team rally and theirs they were so sticking to each other and your team is going solo or duo in fights you can't win them even you know how to play rally is much needed
Difficult game, don't use [full moon assault] at level 1 because then dracula has no damage or healing, the rest was random vs couple + why the fuck thanatos roamer I don't like it good for giving vision YEESSSS but I don't understand what's good about it because the beating they give to the tank they give to you