Your triumph for the Bloom bosses is bugged. Someone in my clan had this issue. Here's how we 'fixed' it: Need two people in the fire team. The person who has the bugged triumph & someone that has already completed the triumph. Because Koftiks is 'bugged' for one of the players, doing an overthrow in the Bloom will automatically summon Koftiks as the boss every time, so you're stuck in an infinite loop of killing it and never getting a completion. Do the overthrow up to the point where Koftiks is summoned. The person with the bugged triumph fast travels to the Lost City and hangs out with the ghost shell vendor while the person with the unbugged/completed triumph repeatedly fast travels to the Bloom until a boss other than Koftiks appears. It may take quite a few tries to get a boss besides Koftiks, so be patient. At that point, the person with the bugged triumph can rejoin their team mate and kill the new boss. Stay in the Bloom, wait until all the enemies respawn, redo the entire process to summon another overthrow boss - which should be Koftiks. Kill it & the triumph should complete. That worked for us, hopefully it will work for others as well, if they feel like dealing with extra hoops to jump through.