"What the fuck?"
What Erik was seeing was as horrifying as it was incredible. Vania almost got as powerful as the Cerulean bird, at least in terms of strength. Of course, her mana was a third of what the beast had. Nevertheless, it was incredible the jump in strength she just got. Vania turned by far into the most powerful human who ever existed.
Her power level had increased exponentially, surpassing even his own. The problem was that she likely lost all reason, based on what Erik was seeing.
Vania was dangerous before she got the serum, but now it was even worse.
[You still have essence flow. Even if she is faster than you, with the hydra's heads and infinite mana, you should be able to kill her.]
Which was a variable. Vania had monstrous amounts of strength and dexterity, meaning Erik would have to try quite a lot to injure her.