As you progress throughout the story, you will be faced with certain decisions that can be good or evil. These are Karma moments and they reflect whether Delsin will be good or evil. Outside of those set choices, you will also be given choices in general gameplay, such as killing a wounded enemy or restraining them. Both Good and Evil Karma have five levels each, with higher levels unlocking more abilities for powers.
Karma Bombs are the super move that Delsin has access to with every power (except the last one). These moves are only available when the meter in the top left corner of the screen is maxed out and flashing. Both Good and Evil Karma have you performing the respective actions in order to fill the necessary meter. However, they differ in the long run, as each one has slightly different mechanics.
For Good Karma, the meter will always stay where it’s at, unless you do an evil action. For Evil Karma, the meter is time-based, so it will empty to zero if you take too much in between evil actions, as well as perform a good action.