I m a huge fan or resident evil played all of it, and I must say that lady would be OK In most situation in resident evil, she can defeat zombie liker and hunter easyz she cans defeat tyrant too, think she would survive everything but I don't think she is able to beat wesker without inject him whit the serum PG67A/W
However during a battle with wesker she would probably be able to take him by surprise and shoot a rocket at him and subdue him for few second and inject the serum at him just like Chris and Sheva, but whitout the serum there is no actual normal weapon that can beat wesker and lady could not be able to beat him
She was able to fight vergil and Dante (even if dante was just playing whit her) and survive... Also during mission 16 in dmc 3 she seems to be very fast during gameplay and dodge dante attack, so she should be able to keep up whit wesker a bit
