In the first stage the warrior is surrounded by dark purple mist and emits a Afterimage-like distortion, in the second stage, it is identical to the first one except it now gains red sparks similar to the blue ones of Super Saiyan 2, in the third stage, the aura gains a dark red aura similar to the Evil Aura and is even capable of affecting the surrounding area, while having has his or her goals and ideals rewritten. The spell can be broken by putting some sense on the victim's head or even by simply asking what they are doing that which usually makes them unable to answer correctly.
Depending on who and when the spell is used, the results can be totally different. It seems to be incomplete according to Giblet, who stated that even with the perfected version, he is far away from reaching the Super Saiyan God form. Additionally as shown by Giblet, the third stage can be used in conjunction with Super Saiyan God, despite its divine nature. Additionally Red Ribbon Androids such as Android 13, Android 19, & Android 20 who normally lack a Ki signature will gain one if empowered by Dark Ki allowing them to be detected via Ki Sense as a side effect, a notable weakness as it removes said Androids' stealth advantage as they can be sensed while utilizing Dark Ki.
Usage and Power
It was initially used on Raditz, who, instead of being a prideful Saiyan, he just wanted to destroy everyone on his way, especially Vegeta and Nappa, after realizing Shallot was trained by them. Despite his Ki "skyrocketing", he was unable to defeat Gohan (from before his battle against Vegeta and Nappa), Shallot and Zahha combined power.
Turles was the next one who displayed that form, instead of searching for power and govern the universe, he simply started dozens of senseless conflict, changing his side constantly, only to generate even more battles. When asked by Shallot why he was doing such things, he was unable to say why and was ultimately defeated by Shallot's newfound power.
Dr. Gero and all his remote-controlled clones were brainwashed, making them believe that people only would respect his science if he creates the Ultimate Warrior. Even when the original Dr. Gero was killed, his Clones were still brainwashed, however, the spell was broken when Android 16 made him remember his original goal.
In the middle of the Super Cell Games, Ribrianne was revealed to being brainwashed. She became even more "extremist" about love, saying, and doing things that even Kakunsa and Roasie were unable to agree. She was released from the spell when Shallot made her realize that she was hurting her friends.
Kale was brainwashed in front of Shallot and Caulifla by Babidi, the spell was slightly different this time, instead of changing Kale ideals and goals, he just took advantage from Kale weak heart, making her believe that Shallot and Caulifla were a couple. She was ultimately freed thanks to Caulifla and Shallot.
When Babidi menaced to destroy every single human on the Earth, uncountable combatants and Saibamen were brainwashed to help him on such thing, however, it is more like they just are on a mindless state and not with his ideals and goals rewritten. Bojack was brainwashed on that conflict as well, his arrogance and sadism skyrocketed alongside his Ki, making him call himself as "The King of Universe", but he was ultimately defeated by Adult Gohan, Cabba and a teenage Future Trunks.
After Beerus realized that Babidi wasn't the mastermind behind this whole tournament, he asked why Babidi was gathering so much energy, a question which he was unable to answer. He doesn't seem to be powered up by such technique but only had his memories hugely rewritten. However this doesn't stop Giblet from killing him as he had outlived his usefulness to both Giblet and the Mastermind.
Giblet was revealed to be powered-up by the technique, and even is an ally of the mastermind, demonstrating an improved version of the technique, being able to rival with Super Saiyan 3 Shallot, however, he was no match for Super Saiyan God Goku.
When Shallot, Bulma, and Jaco returned to Earth, they found Nail fighting a powered up Lord Slug. While Shallot stated that he didn't even need to turn into Super Saiyan to defeat Slug, he noted that he was constantly getting stronger instead of just receiving a single boost on his power. Instead of being brainwashed, memories of every single battle that Shallot had were implanted on his mind.
Later in the game, Shallot fights against Majin Vegeta, who was being powered-up by the Improved Version of the technique displayed by Giblet, while he was initially able to overpower Super Saiyan 2 Shallot, he was no match for Super Saiyan 3 Shallot. Likely Giblet and Super Buu, Vegeta wasn't brainwashed by the technique, but instead is simply being powered-up by it, since he is an actual ally of the Mastermind. Majin Vegeta's Dark Ki empowerment shows that Dark Ki can be used in conjunction with Manipulation Sorcery (it should be noted that Majin Vegeta is still under the influence of his era's Babidi and not the Babidi who Zahha was manipulating).
During Team Beerus' mission to have Shallot become a Super Saiyan God via the Super Saiyan God ritual, the Mastermind sends several tournament participants empowered by Dark Ki to stop him. Among those under the effects of the Dark Ki, includes Kaiwareman, Tennenman, Combatants such as Raspberry, Thouser, and Zangya.
A Frost from before the events of the Tournament of Destroyers was powered-up by the perfected version of the Dark Ki, but his case was the same as Lord Slug, instead of being brainwashed, he now knows everything about Shallot and every battle he had.
Zahha acting in his role as Shallot's ally, summons various Tournament participants who Shallot had helped to keep the Dark Ki empowered warriors at bay, so Shallot and his righteous Saiyan allies can complete the ritual.
The technique was proved to be able to brainwash even likes of Android 13, an Artificial Being though this isn't surprising given Dark Ki was able to brainwash his creator Dr. Gero and several remote controlled Android 20s. Despite being an ally of Mastermind, he was brainwashed instead of just being powered-up like Zamasu, Vegeta, and Super Buu. Android 15 noted that he totally forget about their original goal of destroying every Goku from the history, and instead was simply trying to kill Shallot, which was just a sub-note on their original goal.
Later on, after being powered up further by the mastermind, Super Buu unveils another stage of Dark Ki after being enraged by Shallot. The power is so intense, that he alters the surroundings nearby to turn into a lighter shade of purple. In this stage, Super Buu is shown to have is seen to have a black outer aura, with a dark crimson inner aura. The game sprite shows that Super Buu has a dark violet sort of aura. This stage of dark ki was enough to overwhelm Super Saiyan God Shallot, who was using the same amount of power as the last fight against Super Buu. The tides soon changed however, when Shallot used further amounts of power.
After forcefully spitting out Piccolo, Ultimate Gohan and Good Buu, Super Buu turns into Kid Buu and begins fighting Shallot & Zahha. A short while after, Kid Buu reveals that he has this stage of dark ki as well, whilst fighting against a fatigued Super Saiyan God Shallot.
After being overpowered by Super Saiyan 2 Shallot, General Rilldo uses the second stage of Dark Ki to try and gain an advantage over Shallot. However, he is defeated by Super Saiyan God Shallot. Despite this, Rilldo powered himself up even further, at the risk of damaging his body to prove his undying loyalty to Zahha.
The Dark Saiyan God Giblet
During Super Saiyan God Shallot and Super Saiyan God Giblet, Giblet advances all the way to the third stage which he uses in conjunction with his Super Saiyan God form. However despite the massive power boost, ultimately Super Saiyan God Shallot was able to prevail.
Ironically, this actually fulfilled Zahha's plan who literally stabs Shallot in the back and reveals himself to be the true Mastermind who had captured the twins (as revealed by Shallot's recurring memory where Giblet is telling him to run with Zahha being the one Giblet was telling his brother to run from in the complete memory) who he places one of two orbs that make up the Omnificence Crystal. Zahha then manipulated their memories (erasing most of Shallot's memory thus being the one responsible for his amnesia) and used a combination of subtle manipulation and Dark Ki to foster Giblet's hatred of Shallot and the modern Saiyan descendants of the Evil Saiyans who wiped out the righteous Ancient Saiyan subspecies that the twin Saiyans belong to, all to facilitate a "Battle of Super Saiyan Gods" to perfect the Omnificence Crystal, a failed prototype Super Dragon Ball. Removing the orbs from the two brothers, Zahha completes the Omnificence Crystal which can grant any wish as long as it is supplied enough Kili.
Video Game Appearances
In Dragon Ball Legends, certain characters are empowered with Dark Ki during the main story. One aspect of Dark Ki empowerment, is that it grants the user the DRK Element which is stronger than the main elements BLU, GRN, PUR, RED, & YEL. However DRK is weak to Shallot's LGT Element, thus all Dark Ki users have a elemental disadvantage against him.