Buy RS3 Revenant bane off-hand longsword
The revenant bane off-hand longsword is a tier 79 melee weapon in RuneScape 3. It goes in the off-hand slot and uses the slash style. You need level 80 Attack to wield it.
This weapon is a bane off hand longsword + 4 that has been upgraded with a corrupt Ancient Warriors' melee weapon. It has 1876 accuracy and 483.9 ability damage. It is tuned against revenants, so it boosts your auto attack damage when you fight them. It does not boost ability damage against revenants. Only the two-handed and main-hand revenant bane swords do that.
Pair it with a main-hand weapon for strong dual-wield melee combat. It can be augmented into an augmented revenant bane off-hand longsword if you want to add perks.
The weapon degrades over 50,000 charges of combat and then breaks to a repairable state. A full repair costs 400,000 coins at base price, and the cost scales with how damaged it is. You can repair it for less at an armour stand or whetstone. It is a light weapon at just 0.08 kg and was released on 7 January 2019.