The Mutilator is a bracelet-like device presumably of Sirian origin. According to NETRICSA, it can only analyze limited statistical data from the object. The device itself appears to be mostly made of gold or a metallic texture, with a black orb on it surrounded by four smaller blue orbs. As a weapon, the Mutilator doesn't have an ammo count, but does have a cool-down if it is used too often. This is identified by the blue bar rotating clockwise around the black orb. Once the blue bar has rotated all the way, it will overheat, and won't be usable until the bar has reset.
When used on an enemy, the Mutilator releases a light blue energy beam that lassos onto the target. Depending on the size of the target, the Mutilator will either dismember the enemy or kill it after the beam has been released. A player can identify when a significant charge has been achieved for enemies by looking and seeing whether the black orb begins to glow red, which signifies the beam is powerful enough to dismember whatever enemy is lassoed at the moment. The Mutilator will also make a specific sound which can also serve as a notification when to release a charge.
The Mutilator also works on non-organic matter as well, such as pillars, walls, or statues, making it useful for eliminating obstacles that are in the player's path. It doesn’t work with all objects.
Since each enemy has a unique value as to how long they must be lassoed before being able to release a charge to kill the victim, it is not an advisable weapon for every situation. The larger the enemy, the longer the player must keep the victim lassoed, sometimes long enough to near the overheating threshold.
The player can still be easily overwhelmed despite being able to target small groups at a time with this weapon. Larger enemies such as Khnums, Major Bio-mechanoids and Scrapjacks will actually pull the lasso beam, thus bringing Sam much closer to each one.
In a similar manner, Sirian Werebulls won't be immobilized by the beam and continue running, potentially dragging Sam around with them. This can be extremely dangerous when dealing with Khnums, and Major Bio-mechanoids, as each can deal a significant amount of damage at close range. With enough practice, though, an experienced player can kill multiple Werebulls with the Mutilator once they are in range.
Despite it pulling the player, it is entirely possible to kill such enemies with the Mutilator once the charge has been achieved, and released. However, Khnums cannot be killed with the Mutilator with one player, in order to kill a Khnum with a Mutilator, another player must assist with their Mutilator.
With enough practice, a skilled player can take out entire small to medium-sized groups of Kamikazes or Kleer Skeletons with the Mutilator.
It could be that the Mutilator didn't exist in early design stages, but instead there was a time-traveling gauntlet device.
Seeing the concept, the character in the sketch goes "poof" in the end, and combining it with the fact that there's a scrapped time-traveling feature (or "history switch" feature) found in the editor (at GlobalGameParameters.rsc), it could be very possible that it used to be a time-traveling device.
It is unknown how exactly it would work, but looking at the feature at the editor, it probably was to be temporary, time-travel duration could be extended by picking up certain (?) items (with a max "History Time Extension" of 5), and it also could fail ("History Switch Failure Sound"), but these are speculations.
Maybe that is the reason why the Sirian Mutilator used combined sounds from other weapons from the game.