I have been grinding Festival of Lost, it's very rewarding. 600 AR Horror Story is a must have, excellent in PVP & PVE, well balanced AR. Remember to wear your mask otherwise you do less damage. Keep in mind, you can only get 3 Horror Story AR, one per character. I would recommend grind with warlock, New Arc class, weapon rift and Luna boots. It melts the boss. Weapons: DFA, EP shotgun, sleeper. Loots: Don't go straight, go right 2nd block area, then chest area. 2 jumps. Use fire team medallion to increase your chances of getting prime engrams. You will get many. My characters has hyper jumped 20+ lights each because of Festival of Lost activity, awesome way to grind and speed leveling up. Anyone tried using track canon on the dark Knight? Push off the cliff? Do you get anything? More to come...