ooohh that yeah thats the hardest boss in the game.
first of all go and grind a shit ton and finish the beehive chapter
second it isn´t blocking anything you cant go through the path after you defeat it
third when you defeat it drops a legendary item that you can bring to the black lady and craft one of two legendary weapons to Niven or to maeve i think but you can only craft one of these so chose wisley
i hope this can maybe help you a little