Here are a few tips to complete this on Pro difficulty:
* First section has no enemies but one shows up after you get a crest. You dont need to fight this one and just run past him.
* 2 enemies in the dungeon you can kill as you have plenty of grenades and ammo
* When hunting for Moon and Sun crest you dont actually need to kill the 2 enemies but it would help alot. Use all your remaining ammo on them as you will lose your weapons anyway.
* When using the different colored cranks try to lure the enemies under the spikes. Dont worry about Jill as enemies tend to ignore her and go after you. Use flash grenades when cornered to escape. When the spikes fall and enemy holds up his spear to prevent getting crushed, just run up and punch them in the face, you will have enough time to run out of there before spikes fall.
* Fight against Wesker is easy, just run around in circles until the fight is over. Dont bother to fight him as you will easily lose since his damage is insanely high!
* Enjoy the achievement