Blister

root@bandit-db:~$ cat description.txt

Epic Bandit class mod for Krieg the Psycho, built around Fuel the Blood, Blood Overdrive, and Blood Bath. Extends grenade capacity and kill skill duration.

root@bandit-db:~$ cat notes.txt

If this mod pushes you above your normal grenade limit, any extra grenades are lost when you unequip it. It originally boosted Boiling Blood rather than Blood Bath, which was corrected in the 25 September hotfix and later rolled into Patch 1.8 (11 February 2014).