I was thinking Halo 5: Guardians should have assassinations that utilize the weapon the Spartan is currently using so I came up with a few ideas. Be sure to add your own as well.
Pistol Assassination (Works for all pistols):
Spartan rotates enemy so they are facing one another. Spartan sweeps knife from left to right using his left hand causing the enemy to bend over. While left hand is temporarily situated on the right side of the spartan’s body, he pulls out his pistol brings it under his left arm and finishes the assassination with a headshot, shooting the bent over spartan.
Rifle Assassination (Works for all rifles):
Spartan brings the enemy spartan onto his knees by holding the rifle in a horizontal manner and driving into the the back of the enemy’s knee joints (sort of like a melee). From there he uses his right leg to push the enemy spartan onto the ground so he is lying on the ground with his head facing down. The spartan then lowers his rifle to the enemy’s head and shoots.
Energy Sword Assassination:
Spartan drives energy sword through the back of the enemy spartan, lifting him off the ground. After stabbing the enemy the spartan retracts the sword and the now assassinated enemy falls to the ground.
Gravity Hammer Assassination:
Spartan sweeps the legs of the enemy using the back part of the hammer (which if you do not know is sharp, but does not have the same “gravity” effect). When the enemy spartan in in midair he brings the front of the hammer down on his jest throwing his to the ground on his back.
Shotgun Assassination:
Works the same as the rifle assassination except that it doesn’t end with a headshot, but rather forceful shot to the back.
Rocket Assassinations (Would work for all weapons utilizing explosive ammo):
Spartan jumps onto the enemy spartan’s soldiers and uses them to push off (backward) into midair. From their the exploding projectile is shot at the enemy who is then blown up while the spartan who shot the projectile is still in midair, a safe distance away. (If there is not enough room to perform this assassination then a default assassination will be performed)
Ideally these special assassinations would have to be unlocked. However, the default assassinations (meaning the usual assassinations) would still be available for everybody to use (unless the player wants to turn assassinations off all together and just use the back smack).