K.C. (Nuka-World)

In the Nuka-World (add-on) for Fallout 4, you find a dead body named Sykes with a letter addressed to him by a man named K.C.

Fate and Jet
Fate is K.C.'s favorite minigun which K.C. is quoted as saying "I loved that damn minigun more than your life." Which he stated in his letter to Sykes in Sykes' old letter. Sykes sold Fate for 100 bottle caps and Sykes also sold K.C.'s Jet which is one of many chems (or drug).