Alright guys, so me and my friends just completed the entire DLC (Story & Side Missions). Now I have to say, he must be the hardest MFer to beat. Just because you cannot deal direct damage to him. Anyways, after we beat him, we went to go at it again and we got this message: "One or more players in your party have beaten this boss today." Something like that, so that means we CANNOT farm this boss AT ALL unless someone finds a way around it. From what I know so far, Seraph Crystals are dropped by the two raid bosses. Hyperius & Master Gee the Invincible. They dropped a total of 7 each. Each gun in the Seraph Crystal Black market costs 120 Crystals.... I hope some of this info helps you guys. Happy hunting (& once a day farming).
Everyone in the party just needs to go into thier xbox settings and advance the time and date, well that is what i have been told. then go back and do it again and so on.
there is two ways you can handle this one Just mod your crystals like true said and two you can mod where u can farm him more then once a day with the gib save editor for the game you have to mode it everytime you beat him back ot 0 sec and you can farm him again done it 3 time today hope this info help you if u want to farm him