From Halopedia, the Halo wiki
During the Installation 07 conflict, Chak 'Lok interrogated human POWs in a facility called the Tower. Once all valuable intel about the UNSC resistance effort on Installation 07 had been wrung out of the prisoners, Chak 'Lok would send them on to the House of Reckoning. One of the captives held at the Tower was Spartan Hudson Griffin, who was taken prisoner following a failed attempt to assassinate War Chief Escharum. Chak 'Lok also tortured a captured combat medic, Lucas Browning, before handing the human over to the Harbinger, who expressed annoyance at the damage Chak 'Lok had done to the prisoner.
After John-117 was confirmed by Banished leadership to have returned in May 2560, Chak 'Lok set a trap by activating a distress signal within Griffin's armor, which the Weapon picked up and the Spartan predictably pursued. Chak 'Lok ordered the facility put into lockdown when the Master Chief arrived and taunted him via hologram, claiming the SPARTAN-II would never get inside the Tower. However, with the help of the Weapon, the Master Chief located the security building that controlled the lockdown, lifted it, and ascended into the main structure. John-117 eventually confronted Chak 'Lok, who was torturing Spartan Griffin. The two fought one-on-one and John-117 killed Chak 'Lok despite the latter using his cloak to his advantage. Unfortunately, it was too late for Griffin, who died from his injuries soon after.
Following Chak 'Lok's death, Glibnub, the Unggoy communications officer operating the propaganda towers across the Halo, claimed that Chak 'Lok was still "100% alive" and that the Tower had simply been closed for "renovations."
Personality and traits
Chak 'Lok often spoke in a calm, polite manner, even when addressing his enemies. However, he quickly dropped this demeanor once battle started. Chak 'Lok enjoyed torturing his prisoners both physically and mentally. Arrogant and prideful, he displayed no concern when the Master Chief attacked the Tower. He held a low view of humans in general, regarding them as being soft and easy to break. Like many Sangheili, he also viewed the Jiralhanae with contempt, though he was still a loyal follower of Escharum. Chak 'Lok also regarded the Harbinger with a certain degree of reverence, viewing her words as "the truth".
List of appearances