Borderlands 4 may aim to make up for BL3's villains' shortcomings with a darker and more dangerous antagonist, in the vein of Jack. Gearbox clarified that Handsome Jack won't be the main villain ...

Update: Well, about twenty minutes after publishing this post, Gearbox’s Randy Pitchford nuked this entire theory, saying that the character in question in the teaser is not Handsome Jack Well ...