Lara's Doppelgänger
Lara's Doppleganger is a double of Lara Croft, created by Jacqueline Natla, Who is an enemy of Lara. The Doppleganger is granted superhuman abilites.
Natla created a doppleganger before in original Tomb Raider and Tomb Raider Underworld. But the first doppleganger cannot moves on its own will. It mirrored Lara's movements. Apparently Jacqueline Natla perfected her design and created second doppleganger who's stronger and has the mind of its own.
Lara found the way to control her after discovered the artifact beneath the now destroyed Croft Manor (Beneath The Ashes). By saying the phrase "Okh Eshivar", Lara managed to make it stop attacking her and killed Jacqueline Natla (who still survived after being hit by the Mjolnir) instead. Thus, freed it from any master.