While Erza was on her mission, she found that Natsu under her made her foot very comfortable. She frequently grinded her sole on him because it felt so pleasing. It seems whatever shrunk Natsu, also made him rubbery in nature. Nothing he could control, but he was gummy in nature. He absorbed an incredible amount of sweat inside of Erza's boot, that it really didn't help his situation in being rubbery, in fact, in made him more so, and he kind of spread out throughout the insole. This happened at around 5 days after she left for her mission. She triumphantly shouted to herself, "I have successfully tamed this bug!"
Natsu was having a much worse time. All he could breath was stinky foot stench. All he could see was stinky foot flesh. All he could taste was stinky foot sweat. All he could feel was stinky foot. All because Erza thought he was a bug. Poor Natsu. He felt that he had flattened out to the shape of an insole, yet he could do nothing about it. Five days later, Erza returned to the guild.
She walked in a noticed and small hint of foot sweat in the air, undoubtedly from her last foot wear removal. She shouted, "My Friends! Come to me! I have great news to share with you!". She gathered only the girls from the guild. They were, Lucy, Juvia, Cana, Evergreen, Wendy, Levy, and Mirajane. She began to tug at her boot again. As the girls tried to scatter, Erza yelled with authority, "SIT!!" Afraid of angering her, all the girls sat. Erza removed her boot and tossed the insole looking Natsu onto the ground. He hit the ground with a squelch from how much of Erza's foot sweat he had absorbed. "My friends, I have found the ultimate foot cushion. The bug that I tamed has given itself to me, and taken the shape of my foot. It even provides a cooling mechanism for my foot. It absorbs my sweat when my feet get sweaty, and it no longer tries to escape.
Natsu was sick hearing this. He didn't try to escape because he couldn't. His magic didn't work, and Erza's constant grinding had reformed him. Erza continued, "You will all experience the delight of this small creature, clearly built to be under our feet." The girls looked a bit skeptical. Lucy, Cana, and Evergreen looked interested, Juvia was only concerned with her love for Gray, and Wendy, Levy, and Mirajane, looked like they felt pity for Natsu. Unknown to them, there was another person watching...It was Ultear. She was still involving herself with dark magic, and was the one who made the food which shrunk Natsu. Erza continued even further, "Lucy! You will be the first. Come, take of your boot." Lucy grew shy. She spoke, "No, it's ok, someone else can give it a try", Erza sternly replied, "Nonsense! You will experience this delight." She went over, held Lucy down, and pulled both her boots off. "There, now we can begin." All the girls recoiled at the surprisingly enormously disgusting smell from Lucy's boots. "I barely have enough to pay my rent! How could I afford new boots?!" she yelled. Erza was about to shove the Natsu Insole into Lucy's boot when Lucy interrupted, "Wait!...Isn't that uncomfortable, having it in just ONE insole?" Erza thought for a moment, and then proceeded to tear Natsu in half. Natsu was in great pain, but for some reason still alive. It was similar to Gildart's separation magic, he was in two, but still Natsu, just in both places at the same time. It was a strange feeling. She then molded him into the shape of an insole again.
"There!" Erza finished installing the new Insoles into Lucy's boots. She then proceeded to stuff Lucy's feet back in the boots. Lucy stood and exclaimed, "Wow! Unreal! They feel so good. I can actually feel them breathing!!" Cana and Evergreen looked jealous, they really wanted a try. Meanwhile, Wendy, Levy, and Mirajane still felt bad for the poor thing. Lucy then went home to while feeling her wondrous new insoles.