K'ril is a member of the Tsutsaroth tribe of demons. These were the ruling tribe of a race known as Avernics, which were the slaves of the ruling Infernals, then the Chthonians, until Zamorak led them in an uprising following his ascension.
When he swipes his target once each with his scimitars, he is using his melee attack. When he slams both of them onto the ground and orange flames appear, he is using his magic attack. When he slams both scimitars down and a cloud of black gas spreads out, as well as exclaiming "YARRRRRRR!" then he is using his special attack. After the September God Wars Dungeon update, K'ril still targets one player. However, anybody standing on or one space near that player will also be hit and the damage will be divided between the players, so non-tanking players should stand away from the tank. This attack will drain half of the player's prayer points upon hitting. K'ril Tsutsaroth's special attack is capable of dealing 6000 or more damage depending on damage reduction bonuses.
YARRRRRRR! (Only if using his prayer-draining attack)
Rend them limb from limb!
Flay them all!
If K'ril Tsutsaroth yells "YARRRRRRR!", players will get the following message: "K'ril Tsutsaroth slams through your protection prayer, leaving you feeling drained." After the September God Wars Dungeon update, any players standing on the tanking player will receive the message: "K'ril Tsutsaroth slams through <player name>'s protection prayer, leaving you feeling drained." The special attack will be used regardless of whether players are using prayers or not.
K'ril Tsutsaroth is classified as a greater demon; thus, killing him counts towards any greater demon Slayer task, and also allows a player to take advantage of the abilities of Slayer boosts.
The easiest way to get there is to cast God Wars Dungeon Teleport and then run north to the hole. Once inside the dungeon, the player must run north and jump across the bridge. Alternatively, a Trollheim Teleport can be used to teleport a short distance south of the entrance, from where the player needs to run north, push aside the boulder and then run to the hole.
If a player has access to the Max Guild, they can (re)tune the portal there to teleport directly to the area just outside the big door leading to K'ril Tsutsaroth.
In his chamber, K'ril is accompanied and protected by three demonic bodyguards: Tstanon Karlak (greater demon, melee), Zakl'n Gritch (lesser demon, ranged), and Balfrug Kreeyath (Black demon, mage). Upon spawning, he will spawn all three bodyguards to fight alongside him. If he is not killed within a certain amount of time, all three will respawn.
K'ril Tsutsaroth appears in The World Wakes, as part of the Zamorakian faction invading Guthix's cave. The Zamorakians' aim was to kill Guthix in order for their god to return, along with the Saradominists, Armadyleans, and Bandosians. After the player fends off against an assault from General Graardor and Zemouregal, K'ril and his forces attack the chambers. However, his attack fails and he quickly retreats after being defeated by the player.
K'ril Tsutsaroth makes a small appearance in Missing, Presumed Death. He is at the Empyrean Citadel on behalf of Zamorak, who is attending Sliske's Grand Ascendency. His audio changes slightly depending on if the player follows Zamorak and/or fought for Zamorak during the Battle of Lumbridge.
Before 31 December 2010, K'ril Tsutsaroth used to give Slayer XP as a lesser demon, rather than a greater demon.
According to the 16th "Chronicles of Bilrach", Bilrach created and summoned K'ril Tsutsaroth for Zamorak.
K'ril Tsutsaroth battles and defeats Commander Zilyana in a flashback during Ritual of the Mahjarrat. If it were not for Saradomin's intervention and the power of the Stone of Jas, it is unlikely that Zilyana would be alive today, which is a testament to K'ril's power.
Before the Evolution of Combat update, K'ril was the most poisonous monster in all of RuneScape, with a poison damage of 168. Har'Lakk the Riftsplitter's poison could deal more poison damage (up to the point where it would one-hit a player), but only if they stood in a miasma portal for a very long time.
Before Nex was released in an update, K'ril had the highest combat level out of all of the God Wars Bosses, with a combat level of 650.
With Triskelion Treasures update, Zilyana's weakness has been changed from Water spells to Nothing. This makes K'ril the only God Wars Dungeon boss that is weak to a specific type of attack rather than the usual Nothing weakness that the other bosses have.
Due to player complaints on the easiness of K'ril after the release of the Evolution of Combat, Jagex buffed K'ril with the following effects: