What is Hero Enhancement Level?

This is another requirement before you can Evolve or promote a hero to a higher star rank. Similar to leveling up heroes, you have to sacrifice units to increase the selected hero’s enhancement level. The maximum enhancement level is +5.

To do this, tap the Enhance icon in the hero’s Detail screen.

In the following screen, you have to select which units you want to use as fodder. You can select up to 12 units. Once done, pay the required amount of gold to confirm the enhancement.

You’ll see a confirmation screen and how much of your hero’s stats have increased. Enhancement is permanent so you can’t downgrade a hero’s enhancement level. You’ll also see the enhancement level as a green “+X” in your hero’s portrait as shown below.