On Hard Mode, K'ril Tsutsaroth has a few changes in his mechanics, such as no longer having an explicit weakness to fire spells, as well as no longer using his Prayer smashing ability. Like all other hard mode God Wars Dungeon bosses, K'ril can bind players for 250 damage if they are under him. His health increases to 100,000 from 55,000, and he has three special attacks he can activate any time during the fight. He is still poisonous and his bodyguards act as normal.
One viable strategy for soloing K'ril is to use various abilities with Ranged or Magic and run around the room while hugging the walls; players would be able to deal consistent damage and cause K'ril to spend more time making his way to his foe, giving him less opportunities to attack or use special attacks effectively. Players will need to constantly click at the corners of the room if they choose to use this strategy, as casting an ability will cause the player character to stop and face K'ril in order to attack.
Another method for two or more players is having a player tank K'ril's special attacks using a powerful shield such as a merciless kiteshield or a divine spirit shield to use abilities such as Reflect and Debilitate more effectively, while other players act as the DPS role. DPS participants should be to the side or behind K'ril so as not to take damage from his enrage mode special attack. Those acting as DPS should rely on damage-enhancing abilities such as Berserk or Sunshine in order to bring K'ril down as quickly as possible. Darklight and Silverlight do not work against K'ril himself, but they do work against his minions.
K'ril Tsutsaroth will yell Run, coward!, and after a brief pause, will charge towards the player he is targeting until he hits the wall. Simply move to the side and watch K'ril bash his head (he takes some damage from this), then continue attacking. Being caught in this attack (essentially being under him while he charges) will result in moderate damage. K'ril is immune to damage while he is running or hitting the wall. An in-game message will tell the player K'ril prepares to charge.
When K'ril says You cannot stand against Zamorakian might!, he will summon an earth spike under the player he is targeting. Players will be notified when he summons an earth spike by an in-game message stating K'ril Smashes his blade into the ground, which bursts into spikes from the impact. While on the spikes, the player will receive 990 damage every two ticks unless they move off it. Players can lure K'ril over the spike; if he stands over it he will take rapid but weak bleeding damage, between 100-500 every tick. After a short time, the earth spike will disappear.
K'ril Tsutsaroth may become enraged with the player he is attacking, and will shout Die in the name of Zamorak! K'ril will swipe his scimitars in front of him for about 5 seconds, hitting all players in the area in front of him with rapid Magic and Melee attacks. An in-game message will tell the player K'ril becomes enraged, swiping at you with wild but inaccurate strikes. You should try to avoid them. These strikes will hit all players K'ril is facing once per tick for about 8 ticks; this also applies if he is moving during that time.
Players are advised to Surge away to avoid the majority of the attack, after which the fight will resume as normal. These attack are able to hit slightly over 2,000 damage each. If you are unable to run away, casting Anticipation or Freedom is recommended to prevent being bound in place (if you run from him), as well as using either Protect from Melee/Protect from Magic (or their Deflect counterparts) and either Debilitate or Devotion to minimize damage; Immortality is also a viable option if players are taking too much damage.
While K'ril is in his enraged mode, he will swing his blades wildly while running towards the player if he cannot reach them. You will know when he finishes when he returns to his normal walking animation.