Trina Riffin

Katrina "Trina" Riffin is Corey's 16-year-old biological sister and the main antagonist of Grojband. She is voiced by Alyson Court. She has an extremely large crush on Nick Mallory.

Biography
Trina usually will partake in some event that the band will be in which means she will sabotage them in some way. While she does try to keep an image of being popular and fashionable, she is secretly a nerd with a talent and love for math and puzzles. Despite her intelligence she was held back in school for three years.

Trina is very intelligent and strategic in her everyday life. She usually use her wits to stop Grojband at playing a gig which usually will hinder them. In Math of Kon she reveals she uses mathematical equations to figure out the best way to destroy her foes. Trina is shown to be fearless and athletic. In Creep-Away Camp she attacked Blade Stabbington in anger instead of being scared and in Helmet she jumped from the second floor onto a hanging disco ball. She credits her fearlessness to her childhood safety charm Mr.Mooseface, a stuffed toy moose. Trina is still scared of somethings such as puppets.[8] She is commanding and goal driven as seen in Queen Bee when she scared all the other contestants away and even manage to command a swarm of bees.

In the episode DreamReaver, it is revealed that Trina's real name is Katrina and has locked up the good side of herself within the depths of her mind; this is shown as a loving sisterly side and refers to Corey as "[her] rockstar little brother." While this side of her can reveal herself at anytime she feels that would be "totally unobedient."

Appearance
Trina is a tall, very slender, 16 year old girl who has bright, long, pink hair that goes down to her shoulders and a purple head band and thick black eyebrows. She wears braces (sometimes the music hurts them), a white shirt, a purple skirt with pink leggings under it, white knee socks and black shoes. She also wears eyeliner.

Personality
Trina Riffin is a very emotional 16 year old girl who mostly has trouble with her anger. Trina is a very sensitive and trigger-happy girl who is always seen yelling and getting mad over little things. She seems to insult, hurt, abuse, and just be mean to everything and everyone around her to take out her anger. She mostly does this to her friend Mina, who she treats like a slave. She forces Mina to do whatever she wants and always treats her like dirt instead of thanking her. Although it may seem as though Trina is mad all the time because there are bad things happening to her, sometimes Trina seems to get mad and be mean even when nothing has happened to her. Trina hates her brother Corey and his band with a burning passion. She is always seen trying to destroy his band and ruin everything for them.

Corey Riffin
Corey and Trina are siblings. They have a very bad sibling relationship and both hate each other. While Corey annoys her, she is generally rude to him. If it wasn't for her and her angst-filled diary entries, the band's lyrics wouldn't be any good. She always tries to ruin Grojband's gigs, but, more often than not, fails. She tried to kill him on one or more occasion.

Mina Beff
Mina is a friend of Trina. While Mina thinks highly of her best friend, Trina thinks of her as a nuisance, not caring about her safety and feelings when ordering her around and never treats her like a friend. However, they do have a lot in common like the love of math and puzzles. Trina use to be nice to her kingergarten until High school and Mina is waiting for the niceness of Trina to return.

Nick Mallory
Trina has a crush on Nick. When he's around her, she gets dreamed-out and lovestruck. Nick is not shown to return her affection, though is shown to somewhat like her as a friend.

The Newmans
As Trina hates Grojband, she supports Carrie's Band, as seen in Creep-Away Camp. She calls them a "clear favourite" in the aforementioned episode, and, in Wish Upon a Jug, wishes they were the "biggest band on Earth" (which her genie takes literally, and grows them to be 20+ feet tall)

Trivia

 * It's a running gag in the show for Trina to get extremely angry over something which is mostly caused by Grojband which makes her jump into the air on a geyser of flames and she will angrily write in her diary while heavy metal music plays. This is called Diary Mode and it is how Grojband gets lyrics for their songs.
 * It can be presumed that Trina has magic demon powers because of how she can levitate her diary and pen and can create fire and destruction by writing in it. The way she is constantly seen going into diary mode and causing horrible destruction all around her just by getting mad and writing in her diary may imply that she has demonic powers.
 * Corey and Trina are biologically related. They were both adopted and are being raised by a single father. It is unknown who their biological parents are.
 * In the episode "Kon-Fusion" it was revealed that Trina was allergic to bread.
 * In the episode "Pop Goes the Bubble", it was also revealed that Trina was allergic to bubbles.
 * Trina Riffin seems to be obsessed with the color pink and has a variety of pink things that she usually gives names to that contain the work "pink." For example: She named her pink car "Pinktastic" and she named her pink sweater "Pinkredible."
 * Trina has been seen as a little kid in flashback three times in the series. These episodes are "No Strings Attached," "Indie Road Rager," and "Bee Bop A Loofah."