A good sniper spot is on the ledge right infront of the invisible wall where the Crota shard is. Great vantage point for both towers and nobody will hurt you. The only way you can get hurt is if Crota moves to the side and shoots or if thralls hurt you behind the invisible wall (doesn't happen often). In which case Crota moves to the side, just jump to the opposite exit of the rooms and snipe from there. Another attack for the sword guy is [R1-R1-R2] it does good damage and is faster and safer than spamming R2 3 times Good luck gents