Logan focused on one specific memory of his that he knew was false.
Logan is in a military complex, he remembers that this specific complex is located in Russia. He is dressed in mostly black, he has an eyepiece that is feeding him information and an earpiece so that he can receive orders. He jumps down from crawling through an air vent and lands in the middle of a group of Russian KGB officers. He draws the katana from it's sheath on his back and begins slicing these soldiers to pieces. Blood flies everywhere, bits of flesh moving quickly through the air as Logan moved from person to person. He weaved and dodged, never giving a solid target to be shot at.
"Good, proceed to stage two Logan. Meet up with the team in the command center."
The memory picked up again as Logan reached a command center room. It was littered with pieces of bodies and blood. Standing in the middle of the room was a large, hairy man with fangs who was wearing a similar outfit to Logan. The two nodded acknowledgement to each other , "A bit messy Victor. Did you bring a towel?" The man known as Victor Creed, or Sabretooth, laughed and picked up what looked like most of a soldier's torso. He ripped the remains of the Russian uniform from the body and wiped some blood off of his own uniform. "I just grab them as I find them," he laughed, showing his fangs. The two men then received their orders and continued through the facility. They left no survivors, even those who surrendered, were unarmed, or were sleeping.
Logan hated this memory, the thought of slicing those men to bits sickened him. He may have no qualms about killing in self defense, or even in defense of a greater cause, but killing unarmed men would never sit well with him. No matter who they were. That this memory was implanted as a false memory to give him trust in Sabretooth also disgusted him. He wouldn't mind a memory that consisted of ripping Sabretooth to shreds, but helping him to perform these atrocious acts that amounted to murder? He tried to mentally point this memory out to Xavier so that it could be removed.
At the same time, he wondered what this would feel like, how it would affect him. This would be an interesting experience.