This ability allows Blackjack to copy the Specialist Weapon of enemies that the player kills. However, unlike other abilities, this ability can only be charged by getting non-scorestreak kills and will be fully charged upon five kills (four with Overclock equipped). Blackjack can also kill a different Specialist after said amount of kills to get the option to choose a different Specialist Weapon. Once the second weapon is toggled, it cannot be changed into another specialist weapon until it is completely used up. Addtionally, if Blackjack kills an enemy currently using their Specialist Weapon, he will immediately gain access to the Weapon that the enemy was using.
If a player using Gravity Spikes gets killed after activation but before hitting the ground, they will keep half the bar as if they were using Gravity Spikes with Ruin. However, the player will not keep Gravity Spikes itself. The meter will also show that the player has two and a half kills and the player will need to kill three more enemies before being able to use another weapon (two if the player is using Overclock).
In the case of the scenario above, when the power meter refills, the player will not get Gravity Spikes back; the player will instead receive the Specialist Weapon of the last enemy killed.