I'm rubber, you're glue.
The Seraph Shield Antagonist is manufactured by Maliwan and comes from the Borderlands 2 Assault on Dragon Keep - DLC.
The Shield still deflects bullets when depleted, but won't shoot slag balls.
The Homing Slag Balls will be shot at any enemy that deals damage to the player.
Antagonist's Drop-Rates and all Sources:
3 Epics count as legendary ingredients and may come as a result: Deadly Bloom, Supernova, Cryo Spike