Its an exotic that requires them to hit multiple headshots quickly then get a double bounce and have someone the knife can home in on. You got hit with an athrys embrace strengthened heavy knife. You dont see it often stop being a child. No it is not gamebraking and it can be countered by not sitting by walls being super passive. Also if youre a titan you literally have melee abilities that blind or supress and can also one shot from an exotic effect.