Eva was on a killing spree. She did not care about the who, where, and why. As soon as a Demon entered her field of vision, it would be lanced to death, forever depriving the world origin of the Hell Realm of this little bit of Demonic Origin Energy that could be used to create more Demons.
Eva cleared entire Demonic villages this way, taking down Demons that ranged from the Private rank to the Captain rank. One should note that inside the Tower's universe for floors 31-40, the Demon Race had completely different rankings compared to the Main Plane.
Outside the Tower. Rank 0 would be Infant Demon, though once they grew up they officially started as Rank 1 Inferior Demons and would evolve into Rank 2 Low Demons, Rank 3 Mid Demons, Rank 4 High Demons, Rank 5 Elite Demons, Rank 6 Demon Commanders, and finally, Rank 7 Demon Generals.