When Russell transformed into Alice, he gained the instincts of Alice as a "Doctor."
Although there were no related memories in his mind, cognitively it was as if the memories had been obtained and a form assumed.
Using her own left hand as a medium, Alice utilized the Spiritual Energy of the "Nonexistent Device" to materialize a prosthetic arm Russell had designed in the past.
Russell was very familiar with the internal structure of that prosthetic arm, and therefore, at this moment, Alice could also use the Nonexistent Device to perfectly recreate it.
The "nonexistent" steel prosthetic arm gripped All Cooked's neck tightly and pulled him upwards.
