The episode featured the first "Time Lord-style" regeneration of a female that showed the complete change in physical appearance from old to new incarnation on-screen. Previously, such regenerations were shown with the change from an old form already completed or cut out before the physical change even began. Let's Kill Hitler also dealt with other aspects of regeneration, such as being able to rapidly heal from otherwise fatal injuries while the regenerative cycle was still in process, and a capability to donate some amount of regenerative energy to another at will.