What makes an enjoyable hero?

Hey folks, to put this briefly: as a sort of writing exercise before I take on the daunting task of creating a midara, I’m busy making one of just about every other possible character type. Currently, I’m brainstorming ideas for a hero.

I have a bunch of basic ideas to build up from, but making a main-character type is not something I’m well-accustomed to; I feel much more at home making supporting characters or characters who fit more into the enigmatic side-character idea. So, before I commit fully to the groundwork of my hero Crizice, I’d like to hear some input from the more experienced writers around:
When you read an encounter between a hero and an enemy (especially in regards to characters battling against midara), what aspects of the hero make them interesting to read and inspire you to root for the hero’s side? Even better: when writing a midara, what makes a particular hero fun and interesting to write against?

You know, I don't think this is something I ever actually thought about before.

Well first, all of the characteristic that makes of the character itself which will then govern of how an individual would respond to others. And there are many factors of what actually makes a character, one of which includes a backstory.

Note: I would rate hero kind of loosely as I personally don't really go by good/evil axis, rather than intent and purpose myself.