Ascendant Sword is a Relic used in Crota's End, The Sword of Crota and The Fist of Crota.
Quick Melee Attack
Heavy Melee/Slam Attack
Charged Slam Attack
Lore
This is the world the Hive craves: a universe creased by the edge of the sharpest sword.- Toland, the Shattered
The Cleaver is a Hive melee weapon that is normally carried by Knights. Ordinary cleavers are made of bone and metal and are of little value, but special swords exist that can be wielded by Guardians under specific circumstances.
Usage
Picking up the Cleaver will change the camera perspective to third-person. Pressing the melee button will do a quick swing, which can be tapped rapidly to do a combo. Pressing the fire button will do a more powerful swing. It's possible to string together two quick swings followed by one powerful swing to get a very fast yet powerful combo. Finally, if a player's Supercharge meter is full, activating one's super will make the blade release a shockwave. Switching weapons will drop the sword, though grenades can still be used with the sword.
Sword of Crota
During the story mission the Sword of Crota, the player picks up a cleaver that belonged to Crota. This weapon is said to consume the light of Guardians, but does not adversely affect the player during the mission. The player then has to use it to defeat the three Swarm Princes, after which the sword disintegrates and the mission ends.
Ascendant Sword
As part of the Dark Below, a special knight called the Blade of Crota will sometimes appear on Earth or on the Moon. Killing this knight will drop an Ascendant sword, which functions very much like the Sword of Crota, except that it will break after about 30 seconds. Four swords also appear in the Quest Ritual of Sacrifice. In Crota's End, the Ascendant sword is dropped by Swordbearers, and is the only way to kill Gatekeepers and Crota.