Dipper (Mason) Gleeful is an alternate version of Dipper Pines, from the show Gravity Falls, which is a TV series centred around main characters Dipper and Mabel Pines. In the Reverse Falls AU, the series is about Gideon Pines (who takes the place of Dipper Pines in the original show) And Pacifica Southeast (who takes Mabel's place). Dipper and Mabel Gleeful run the Tent of Telepathy in the Reverse Falls universe and are considered "villains" to the main protagonist, Gideon Pines.
Before you read this, note that the situations, personalities, etc, are based on how the different fan fictions and takes of Reverse Falls are USUALLY written. It CAN vary very much, though.
Dipper, like his sister, is almost always seen wearing shades of blue, accompanied by black. Dipper wears a light blue shirt, with black pants, complimented with a belt. He is usually seen donning a cape, with the symbol of the twin's "Tent of Telepathy" on the back.
In some fanart, he is seen to be wearing a pair of blue earrings, similar to his twin. Just like Mabel, he always wears his amulet, his being in the form of a bow tie. But even without his amulet his intelligence and cruelty still make him a powerful enemy.
Compared to the cartoon show, Dipper's first and real name is Mason, but gets the nickname "Dipper" from a birthmark on his forehead that resembles the big dipper constellation. Unlike his Gravity Falls counterpart, he is uncaring about the mark, and does not worry about people judging him for it and therefore doesn't bother to cover up. This has often depicted him as having his hair brushed or slicked back.He likes his hair this way.
Like his sister, Dipper has a lust for power and enjoys the pain of others. He is often seen to be either cold and unfeeling or simply disgusted by the affection or caring of others. Seemingly, the only person he shows any sign of actual care for is his sister and partner Mabel Gleeful, but even that has its limits.
Dipper is extremely intelligent and sly, being able to fool the town into believing him to be a kind and benevolent young man. He has little trouble manipulating others into doing or getting what he wants. This makes him a great threat, with or without his amulet.
However, unlike his sister, Dipper is seen to be slightly more stoic, serious and more disgusted by those he deems pathetic or weak, instead of sinisterly amused like Mabel is shown to be.Both Dipper and Mabel are obsessed with magic, specifically black magic, and will use their shows as means to continue their studies about the magic and anomalies in Gravity Falls. It can be assumed that Dipper as well as his sister are sociopathic and have some levels of emotional detachment as, with his sister, they will secretly kill and/or use the people who 'volunteer' during one of their shows. The one who volunteers will be given a challenge. While the audience is still watching, Dipper and Mabel will use their powers to make the volunteer look 'alive' by making them move even when they are already dead. This can also imply that they are quick-thinking and cunning, as they never get caught.After the show, when the audience is gone, he and Mabel will secretly hide the volunteer's body to later use in magical practices and experiments.
Mabel is Dipper's twin sister and partner in crime. She has been speculated as the only one he cares for in Gravity Falls. At the very least, he does show a great deal of respect for her prowess and he does show signs of immense care for her. He identifies the two of them as partners. Even though they have shown to irritate each other at times; they are mature towards each other and are shown to love each other regardless.
However, Dipper is often annoyed by his sister's constant enthusiasm towards their victims' pain and doesn't like it when she is distracted or not on task. His seriousness nature can sometimes frustrate Mabel, who often deems him a 'killjoy'.
Dipper's love and care for Mabel is shown in a lot of fanart. It is often depicted that when she is hurt, Dipper will either cry for her and/or torture the culprit. He is shown to have a sort of protective complex, as he will attempt to protect her from any danger, regardless of whether or not she can look after herself. Dipper is shown to be frequently agitated when guys dribble over Mabel, seeing them as foolish, his sister a showoff, and (though he won't admit it) he thinks she's too good for them. They have a similar relationship to the GF Pines twins, just with more restraint and won't admit they love each other like the Pines twins do.
It's also to be noted that Dipper is slightly fearful or at least disturbed by his sister's overly violent, sadistic amusement and pleasure of their victim's torture.
The twins are famous for their show and tricks. After frequent visits to the twins's show, Pacifica has developed a secret crush on Dipper, which at first amuses him to the fullest but later Mabel tries to use it to their advantage, seeing as Pacifica doesn't know their true character anyway.However, over time, Dipper becomes less aggravated by Pacifica's positivism, and more confused by her perseverance. Moments when Pacifica displays her intelligence, Dipper is seen impressed, or at the very least intrigued, and when she tries to drag him into her adventures and ideas he usually politely declines and at rare times go with her only to leave shortly after the fact. Overall, it's to be noted he doesn't wish to physically harm her.
Mabel takes note of this and confronts her twin brother, going so far as to openly command him not to fall for Pacifica's 'goody-goody words'. Dipper assures her that everything's is under control and Mabel carries on with the plan on how to take Journal 3 from Gideon.
In many individual takes on Reverse Falls, it has become popular for Dipper and Pacifica to be together, however, this is, like the Gravity Falls storyline, uncanon.
Both of the Gleeful twins' first meetings with Gideon are through his appearance at their show, however when they properly speak to each other, both mention they had already known about a 'new kid' coming to town before hand. When Gideon questions how they knew that, Dipper calmly explains that "...We know everything. Nothing happens in this town without our knowledge first."
At first Gideon is only mildly jealous of Pacifica's adoration over the Gleefuls, Dipper specifically, but when he finally meets them and starts to suspect them, Gideon becomes agitated and more determined to prove the twins' true intentions, but when those intentions are shown to be more diabolical, Gideon claims he must defeat them and protect the town. (Note: Pacfica's constant refusal to give up on Dipper and Mabel fuels Gideon's rage further)
Gideon and Dipper (similar to their Gravity Falls counterparts) are in a bitter rivalry, and tend to despise each other immensely. When Gideon tries to stand up to Dipper, the latter becomes angry over his 'disrespect' and tries to threaten him, but Gideon refuses to back down. Eventually when the twins' start connecting Gideon to other strange occurrences, Dipper sees Gideon more of a threat to their plans, rather than just threat to his pride. Time and time again Gideon has been shown to be able to hold his own against whatever the twins' throw at him, only making Dipper angrier and vow to destroy Gideon at all costs.
The twins have the Will under their control to assist them against his will. Though he was inevitably summoned to deal with Gideon, once the demon was deemed unfit to handle the task, the twins' decided to turn him into their servant. Will can't escape the hands of the twins because they are much more powerful than him. (Note: It is possible that Will purposely didn't harm Gideon and possibly saved him, and the twins are unaware of this). Will is often shown to be used both for his powers and for his vast amount of knowledge by Dipper and Mabel.
Dipper seems to have no problems being cruel to him and is even happy doing so, much to Will's misery. This could be because, unlike human victims, Will cannot be killed, and there is nothing lost in torturing him (unlike the time restraints on human corpses) and that Dipper can reveal more in the fact he has so much control over a powerful dream entity rather than that of ordinary humans or other lesser creatures. Will has also be seen as a the victim of Dipper's pent up frustrations whether or not the problem is even Will's fault. Dipper is notably much crueler to Will than his sister Mabel is.