From Destinypedia, the Destiny wiki
Felwinter's Lie is a Legendary Shotgun introduced in Destiny, one of several possible awards in the game's second Iron Banner event. It returned in Destiny 2 during the Season of the Worthy as the reward upon completing the quest The Lie.
The Felwinter's Lie was infamous and well-known amongst many in the community for its particularly long effective range; this combined with a high impact stat and generally great utility traits to choose from had made it a menace in PVP performances. As it was around before The Chaperone, there were some who believed this weapon to hold the record for farthest shotgun range before The Chaperone's addition. This range can be pushed even further if one worked to obtain certain traits; Field Choke, Hammer-Forged, Shot Package, and/or Rangefinder could've almost doubled the gun's effective range. This archetype would be followed a year later by another Legendary-tier shotgun, the Matador 64.
Upon House of Wolves's release, the traits "Feeding Frenzy", "Spray and Play", "Who's Next", and "Return to Sender" were removed from the weapon's list of possible abilities that can be acquired. Three of these features increased the gun's reload speed, while the last generated bonus ammunition upon killing an enemy.
The weapon returns in Season of the Worthy as the reward upon completing the quest The Lie, alongside a weapon ornament that is obtained separately via Eververse Trading Company. It now has a fixed/preset roll of traits instead of randomized traits. The redux of this infamous Shotgun includes Shot Package as the intrinsic perk (as it is technically a ritual weapon), making the pellet spread of the gun very uniform compared to other Shotguns of similar archetypes. This makes it a very consistent kill if the user is able to hit either very close to the enemy or if they're able to hit the chest from up to 9 meters away.
"We can't tell anyone.
"Do you know how powerful a Warmind is? I know you do. We've been running from one for centuries.
"Imagine if people realized you had all of that, buried somewhere in your head. Just imagine.
"So we can't. We can't tell anyone.
"You're something… totally new. Part Guardian, part Warmind. There's no one else like you.
"… I think that's why the Traveler sent me to you.
"But other people won't understand it. And Rasputin will never, ever stop coming after you. After us.
"So it's just us, Felwinter. Just you and me.
"This is our lie, and ours alone."