Juiced
After 4 or more consecutive deaths, you can move faster after spawning for a short amount of time.
Revenge
After 5 or more consecutive deaths, you can see where the last enemy that killed you is on the map.
Final Stand
After 4 or more deaths, You can get back up after being wounded.
Martyrdom
After 4 or more deaths, you can drop a grenade just after dying to blow up nearby enemies.
Dead Man's Hand
After 6 or more deaths, you can pull out a C4 before death to kill nearby enemies.
Hollow Points
After 5 or more deaths, bullet damage is increased for one kill.

