The Kestrel boomerang is a heavy throwing weapon that can knock down enemies at a distance.
The Kestrel is a melee throwing weapon similar to the Glaive, capable of bouncing off surfaces when thrown. Unlike the Glaive, the Kestrel can knock down any opponents that it hits at range.
Ground Finisher attacks are guaranteed to inflict a Slash bleed proc.
Can be thrown using the charge attack function.
Ragdolls enemies when thrown.
Can be bounced around corners and obstacles to hit enemies in cover.
Projectile speed when thrown is faster than the Glaive. Coupled with its shorter range, you can expect to be able to throw this more often than the Glaive.
See the user build section for builds using this weapon.
Tips
When equipping the Kestrel, the player can throw it and then press the channeling button to detonate the Kestrel, dealing high AoE damage and returns to the player immediately. This is true for all thrown melee weapons.
It can explode in this manner when not equipped and thrown, but the explosion timing cannot be controlled and will often damage the user in close quarters.
The Ground Finisher's bleed proc damage is based on the Ground Finisher damage (which is 30 * 400% = 120 damage without mods). Therefore, the bleed damage can be increased with anything which affects the Ground Finisher, including Channeling and the Finishing Touch mod.
For example, a Kestrel without any mods will deal 42 damage (= 120 * 35%) per bleed tick. With only a fully leveled Finishing Touch, this is increased to 67 damage and to 100 damage while channeling.
Because bleed damage ignores shields, the Kestrel's Ground Finisher can be made into a potent attack against Corpus, especially when combined Toxin elemental mods.
Notes
Can be used to instant-kill most bosses by flinging them into a pit while ragdolled. Loot can be found where they last stood. (Possibly a bug)
When used on a boss they can be permanently stunlocked if a Dethcube is firing at it, causing it to reset the recovery animation. This is fixed by shooting him directly.
Can hit theoretically infinite targets on return.
Like with other thrown weapons, using Whirlwind on the Kestrel will increase flight speed as well as distance travelled, because the flight time is constant. A fully leveled Whirlwind will increase the maximum distance to ~63m.
When not in use, the Kestrel sheaths under your right arm.
Ragdolled enemies' health and shield bars are also concealed while ragdolled. Although they usually display damage indicators while ragdolled, sometimes they will not display if you are not the host - giving the impression that the enemy is invulnerable (not the case).
Sometimes it will continuously fly around its user in a circular path indefinitely after bouncing off at least 2 objects, such as two adjacent walls, if the user stands back and stays still afterwards. (Possibly intended but its exact mechanics are unknown, however, Rebound and Whirlwind were installed when this was discovered.)
Simply installing a max rank Entropy Flight mod will also cause this. The Kestrel is considered flying on a return path the entire time, so it punches through everything it hits. If the player moves too quickly, they will catch the Kestrel; however, if it is carefully maintained, it can continually fly around the player and deal large amounts of damage to everyone in the vicinity.
High flight speed, which causes this orbiting behavior, does carry some risk, as a current bug can cause the thrown weapon to disappear, disabling melee for the rest of the level or until the player has died & revived.
Trivia
The Kestrel is a carnivorous bird in the falcon family known for hovering.
The Kestrel shares the same sheath style with the other thrown melee weapons, where they retract and attach under the right arm.