EVA

Nova (previously called "EVA") is the original infected female hero that you've cured by completing the first 12 chapters of the campaign section. With the 4 full doses given to her, she becomes fully cured and activated. She is in the "Research Center" building in a player's sanctuary and provides a combination of military and economy boosts in stats through leveling her up and applying upgrades to skill areas. As a player kills zombies, takes out zombie lairs, participates in events, etc., they will often receive "Nova Mil. Pts" (red gems) and "Nova Ecn. Pts" (blue-green gems) which are then used to upgrade various military and economy skills. Certain skills require Nova be a certain level herself, and that is done using "Nova EXP" items also given through rewards and events. As Nova is upgraded, additional skills unlock for upgrading. You will see the level required for her next to the skill if she doesn't yet meet the requirement for that skill.

The skills that can be upgraded are as follows:

Military:


 * Fighter ATK
 * Rider ATK
 * Shooter ATK
 * Troop Size
 * Vehicle ATK
 * Fighter HP
 * Rider HP
 * Shooter HP
 * Vehicle HP
 * Troop DEF
 * Troop HP
 * Troop HP
 * Troop ATK
 * Troop Technique

Economy:


 * Food Gathering
 * Wood Gathering
 * Troop Load
 * Build Speed
 * Steel Gathering
 * Research Speed
 * Gas Gathering
 * Resource Gathering
 * March Speed
 * Training Speed
 * Miraculous Survival
 * Troop Armor

TIP: It's worth noting that as you upgrade the building, the cost of upgrading skills goes down. So, it's worth completely resetting Nova from time to time with reset tokens called "Modifying Kits". When you use a Modifying Kit, it resets Nova skill to Lv. 1 and returns all resources consumed. With all the resources still at hand, you now can start upgrading all the skills, but this time at a less expensive cost, meaning you might be able to squeeze more levels out of certain skills than you had before.

Lastly, Nova possesses 3 skills in her main window:


 * Affinity
 * Praise
 * Gift

Based on the level of the "Research Center" building she resides within, you get "x" interactions per day, starting with 2 per day at the base level. There is no help information about what these three abilities do, however, but if you click on "Gift", it does appear that you get some free items.