Sasshou Sasshou no Mi

The Sasshou Sasshou no Mi ( キルキル ) is a Paramecia type Devil Fruit, in which the user can amplify the killer instincts within one or more people as he or she wishes. Sasshou for “Kill”, in both Viz Manga, and the FUNimation dub, it is called the Kill-Kill Fruit

Strengths and Weakness
The user has the ability to ampifiy the "Killer Instint" within a certian person or a group and even themsleves. The user can also feed off the emotions that this causes, making them grow stronger and gain the best of the best Killer Instinct. The user will suffer the standard weakness of the Devil fruits.