Title says it all. Here is mine:
Story: As of the end of B2, Vaults are scattered all around the world and the Vault Hunters are back and badder as ever. Vaults are searchable areas but one particular Vault is filled with a horrible monster from another universe like the Destroyer. Lilith, Mordercai and Brick will once again appear though they will act like guides to the B2 Vault Haunters. Besides the monster, a new bad guy comes to Pandora with an army of psychotic mercenaries. His name is Handsome Mack, the son of Handsome Jack and older half-brother of Angel. Jack once was in a relationship with a woman on another planet before but their relationship was brief as Jack was busy.
Gameplay: Same as before but with 89 bazillion guns, better perks and some improvements.