Aerial takedowns were definitely not introduced in Uncharted 4, they were already present in Uncharted 3. Here's a video compilation of stealth takedowns in Uncharted 3, and the first one shown is an aerial: This attack was likely introduced in Uncharted 3, from : Drake's Deception features additional stealth moves, such as a "jumping takedown". This attack consists of the Drake jumping from a higher platform onto an enemy below, thereby snapping the enemy's neck or knocking them out.