The creature known as Kestrel was created as a spell by M’Shulla and Gorrum, the Lords of Chaos, it has no form of its own, and it most commonly possesses a human and interacts with the material world that way.
It possessed an unknown man several years ago in an attempt to prevent the formation of a new Hawk and Dove team; also to attempt to bring Hawk in on the side of Chaos in the upcoming mystical war. He fought both Hawk and Dove several times, on one occasion nearly killing Hawk, only the intervention of the new Dove stopped him. In the end, he failed and the mortal shell was destroyed by Kestrel’s creators.
Later, Kestrel possessed Ren Takamori (Hank Hall’s then girlfriend) to lure Hawk and Dove to Druspa Tau, where Kestrel actually succeeded in having Hawk fight on the side of Chaos, but Hawk eventually absorbed the Kestrel spell into himself, effectively destroying it.
Kestrel however, was later seen as part of the Injustice Society.
Recently, Kestrel resurfaced in a new male body and managed to ambush the Teen Titans (including Hawk & Dove) in their own tower, managing to steal the power of Raven’s soulself. The Teen Titans voyaged to Kestrel's lair, despite the odds against them. They manage to defeat Kestrel, with some help from a villain who had managed to escape Kestrel's brainwashing. Kestrel died during the end of the 9th Age of Magic.
Powers and Abilities
Kestrel essentially has very similar powers to Hawk, but boosted considerably. It has claws that can cut through steel and enhanced by magic so hypothetically could cut Superman’s flesh. In all it manifestations, it has displayed a variety of skills including acrobatics, hand-to-hand combat, tracking, impressive stamina, superior strength, and a near invulnerability to physical harm.
Unlike Hawk, Kestrel can change between the Kestrel and host persona at will. Also unlike Hawk, the Kestrel-force has a definite personality that can affect or completely take over its host. This personality is chillingly evil and unrelentingly homicidal.