From Mega Man X: Unit 49.

SWM 02 D1, Doppelganger

"He will infiltrate their ranks and bureaucracy, ascending his position at each transfiguration, learning their deepest secrets and allowing us to strike Earth's Government where they least expect."

A shapeshifter spy Reploid capable of accessing the deepest thoughts and feelings of a target to steal their identity with a "soul transfusion", a process of energy exchange via touch that gradually grants them full knowledge of internal data without harm. Doppelgänger's mind can be described as hollow, following nothing else than assigned missions, and their programming has priority over the emulated identities. Such safeguard ensures feelings and incompatible ideals necessary to their acting won't interfere with their true goals.

ENGINEER NOTES: Doppelgänger may assimilate abilities through stolen Reploid DNA and evolve by changing their own structure. We cannot rule out mind contamination by assimilation of necessary mental components in this process, and so we recommend extreme caution.