The Mask of Reflection is a slayer mask obtainable from Treasure Hunter, or from the Shattered Worlds reward shop for 18 million anima. It has a requirement of level 30 Defence to be worn. It provides several bonuses for players looking to train their Slayer skill, listed below. When the double drops, damage and experience boosts have expired after 500 basilisk kills, the mask will become the Helm of Little Kings which has similar benefits, but does not provide double drops, extra damage or an experience boost.
It also counts as a mirror shield equipped, granting the use of dual wield and two-handed weapons, and allowing mages to gain the benefits of rune-negating staves - this is especially useful against basilisks, as they are weak to air attacks.
Once per day, while wearing the relevant mask, the next assignment the player receives will be basilisks. They will still need to go to a Slayer Master that normally assigns these creatures (Vannaka, Chaeldar, Sumona) – if they do not, the player will be told which Slayer Master assigns them. This does not work if they are in the process of setting up a co-op slayer assignment.
Twice per day, this mask will teleport you directly to a choice of locations where basilisks can be found.
The mask confers the same damage boost against basilisks (but only while on assignment) as the Slayer helm.
Killing basilisks while wearing this mask will grant additional Slayer XP equivalent to the Slayer level required to fight them (in this case, 40). This is given regardless of the current assignment the player has, and in addition to assignment and/or contract xp. The XP awarded by the mask can be boosted by items.
Every creature killed is tallied, while the mask is worn. Each mask has a set amount of kills assigned to it that, once reached, "uses up" the Slayer XP and double drops effects, and turns the mask into a helm. The kill count continues to be tracked beyond this point, up to 999,999 kills.
A right-click option outputs total kills of that creature. If the helm has yet to be unlocked, there’s also a message to say how many more kills are needed to do so.
After the helm version has been unlocked, the player is free to switch between it and the mask version, as a cosmetic preference only – this does not restore the Slayer XP and double drop effects to the mask.