The Nine have sent Xur once again to woo us with another set of Exotics for sale. All three classes got useful Exotics this time around while the weapon is more or less a PvE-only item.
Xur is located in Watcher's Grave on Nessus this week. To get to him, jump to the aforementioned waypoint and proceed towards the golden floating barge right in front of you. It's accessed from the nearby rock formation, through the cargo hold. Climb up the ramps and you will see Captain Tentacle near the pile of chests.
Merciless, the fusion rifle, is the Exotic weapon on sale this week. It features a large magazine and an intrinsic perk that makes its charge time go lower each time you don't score a kill with a shot. This makes it fairly useful when taking down bosses as you will have a fusion rifle that shoots extremely fast for the class. Reloading after a kill also increases damage so it's useful for taking down major enemies in one shot, if you kill a minor one beforehand.
Warlocks are getting Nezarec's Sin which is pretty good if you're planning on spamming abilities in PvE since each ability kill restores energy for all abilities. Its use in PvP is limited because you can't reliably kill Guardians with abilities without hampering your own chances of winning duels.
Hunters are getting Gemini Jester which is more useful in PvP since dodging with these panties equipped disorients enemies and removes their radars temporarily. It's extremely annoying to be at the receiving end of this and if you are running 100 mobility, you can spam the radar removal in pretty much every altercation.
Titans' Exotic this week, Peregrine Greaves, is useful in both PvE and PvP, although it's situational in the latter. It boosts the damage of Solar, Void and Arc shoulder charge abilities if you jump before executing them. It is nice to have the boost against stronger enemies in PvE but it really shines in PvP since using the Peregrine Greaves will one-shot everything.
It doesn't matter if the opposing Guardian is in a roaming super or even in a Titan bubble - Peregrine Strike one-shots everything. Just be careful when going up against Hunters with Arc Staff as their melee reach is increased so they can hit you before you shut them down.