To be clear about this it's a member-only event from Alexis's blog

To be clear about this it's a member-only event which will include three brand new Abyssal Slayer Creatures, with the primary goal of it to OSRS GP test the most skilled combatants, as you will require an Abyssal Slayer ability of 95 or above in order to participate. There are more details on this latest event below , as well as the trailer that showcases what you are likely to get from the event.

The city is located in the middle of the city of Senntisten A portal has been opened allowing creatures to move through. Players will be required to fight through the slayer dungeon Senntisten Asylum, and face three new high-level Slayer creatures.

Abyssal Savage (95 Slayer), Abyssal Beast (105 Slayer) and Abyssal Lord (115 Slayer). The Slayer update marks the five year anniversary since the idea of the three demons was revealed to the players in 2017 and has been the most requested update in players in the RuneScape community.

Anyone brave enough will claim powerful rewards, which include armour spikes upgraded to deal more damage, the melee power tier 85 armor helmet to boost adrenaline output, and buy OSRS gold the brand new 92 melee weapon, Abyssal Scourge. Abyssal Scourge.