Herein, what does the knife do in Apex legends?
It's simply a cosmetic item designed to look cool and make you the envy of all your friends and enemies. The Kunai knife can be seen in Wraith's melee attack, intro quip, and Victory pose, too, so you should easily be able to catch a glimpse of it while playing Apex Legends.
Subsequently, question is, how do you get heirlooms in Apex? Apex Legends heirlooms cannot be crafted. You can't even view them in-game until you've unlocked them. Right now, the only method of unlocking them is via Apex Crates. They are the rarest possible drop in the game, but when you do eventually get them, the heirlooms come as a set for each legend.
Keeping this in view, how much is the knife in Apex legends?
The $500 knife. EA's official FAQ about Apex Legends loot tells us the following: “When a player opens an Apex Pack, there is a <1% probability of an Heirloom Set dropping,” and “a player cannot open more than 500 Apex Packs without receiving an Heirloom set.”
Does Wraith knife do damage?
The Wraith Knife is one of the most beautiful melee weapon skins for Wraith mains. Since this knife is essentially just a cosmetic item, it does not affect the gameplay once it's equipped. In other words, the Wraith Knife inflicts the same damage as the regular knife.