It is unknown when Sukuna was able to develop his Domain Expansion, but he was able to use it even after his incarnation.
The environment of Sukuna's Domain Expansion takes the form of a Buddhist shrine that has been disfigured to enshrine a demon such as Sukuna himself. The shrine has horns on the roof, skulls hanging at each of the corners of the roof, mouths coming out of each side of it, and is surrounded with bull-shaped skulls.
Malevolent Shrine is different from other types of Domain Expansions, in that it doesn't create a separate space with a barrier. Because of this, it is considered a truly divine technique, as the ability to realize one's innate domain without using a barrier is akin to an artist drawing a masterpiece on the air instead of on a canvas.
By allowing an escape route, a Binding Vow is formed, which vastly increases the guaranteed hit's effective area with a maximum radius of nearly 200 meters. The radius can be narrowed down if desired.
Within Malevolent Shrine, Sukuna is able to utilize Cleave and Dismantle to relentlessly attack anything in its radius. Sukuna can set it to automatically target any inanimate objects with dismantle, and cleave anything with cursed energy to cut them down.
Sukuna first used it to effortlessly defeat the Finger Bearer. When utilized in Shibuya, Sukuna used it to overwhelm Mahoraga, destroying everything caught within its 140 meter radius in the process.