Proceed through the mission until you leave the air vents, and a cutscene will begin. Hold Select to skip the cutscene. Stealth kill four enemies, and then disposed of the final enemy as desired. After defeating the last enemy, pause the game.
ZZ-CT is a 3x3 method proposed by Chris Tran. It is a variant of the ZZ Method with a unique 2 look LSLL, divided into TSLE and TTLL. TSLE inserts the last edge whilst orienting all corners.
ZZ-CT was created with the intention of fixing everything wrong with ZBLL, and to create the first feasible LL-Skip method under 200 algorithms. Several months of brainstorming and evolution led to ZZ-CT, as reported herein: The core fundamental concept is the orientation of corners before reaching last layer.