Isabel tends to be rather headstrong, and is as quick to fight with her grandfather as she is with malevolent spirits. However she has been shown to be caring of her friends coming to their rescue and attempting to save both Max and Eightfold during the ambush on the Ghost Train. She has also been shown to be somewhat quick thinking, or at least quicker than Max. She is also quite observant, for instance, noticing the Doctopi, 'Pain Killer' reaching out to touch Spender's wound.
Isabel grew up in Mayview, living under the roof of her Grandfather's dojo with his students and her best friend Ed. As a child, a run-in with a particularly fierce doberman pincher left her with a fear of dogs bad enough for the family to give away their own pet. She then received the tool that contained Eightfold from her grandfather, whom she proceeded to bond with. Along with Ed, she attends Mayview Middle School and joined the Activity Club under the leadership of Richard Spender, one of her grandfather's former students as well as her history teacher. She later gains the ire of Susan for not granting an interview about the Activity Club for her journalism project.
Along with Ed, she goes after a Ravenous Gobbledygook eating spirits on the second floor after being informed by a desperate ghost pleading for help and meets Max along the way. Though she's excited to see another spectral, she shoves him into a supply closet for his safety while she went off to beat up the rampaging grudge when the rest of the Activity Club joins her. After Max regains consciousness after defeating the spirit, she introduces herself to him using her tool's powers.
Isabel later receives a call from Max concerning Gorf in his home. Initially unconvinced, she later goes with Ed to help Max out with the spirit, though she stays behind as she had lost a coin toss to see who would go in.
The next day, she and Ed battled and tool'd an eraser spirit before appearing in the clubroom; Isabel sans fingers and Ed sans face.
She has a relatively cold relationship with her grandfather, feeling he is overly strict in her training and prefers to rely on her tool rather than his spectral fist techniques. Although she does not admit it, she desires for her grandfather to see her as a capable fighter.
Ed has frequently been called Isabel's shadow, and the two share a close bond as they both live in the Dojo and have been spectrals the longest. Always appearing together and nearly inseparable, she puts a lot of trust in Ed and enjoys his company as an escape from her grandfather's training. Isabel resents the fact that Ed usually leaves Isabel behind if the situation scares him enough, such as when he scampers off away from an impending lecture from her grandfather. Isabel is later seen to not entirely know what to think about Ed and is somewhat irritated with him.
As the first new spectral her age she's met in years, Isabel was enthusiastic about Max's membership, offering to spar with him and teach him the ropes. She's generally friendly and well meaning to Max, trying to comfort Max regarding Spender's explanation that ghosts cannot be spectrals, by telling him the opposite as she saw that it bothered him. Later on, they promised to watch each others' backs while fighting against the Pixelhounds on the Ghost Train, though Max fell out. Isabel was also horrified and attempted to save Max as he nearly was run over by the Ghost Train.
Eightfold is the spirit possessing Isabel's book. Eightfold was given to her after an incident with a mad dog to help Isabel overcome her trauma. They're fairly close despite Eightfold's eccentric personality and care very much for each other. When Eightfold decided it was time to leave herself behind for Isabel to grow as a person, Isabel was visibly distraught, crying for a moment after it was apparent she was gone for good.
Isabel respects Spender's position as leader of the club and as a teacher, at least enough to fib about her injuries so he wouldn't get in trouble with her grandfather, while Spender gives praise for Isabel's fighting prowess. Despite knowing him her entire life as one of her grandfather's former students, she admits she doesn't know much about him beyond what he does.
Isabel and Isaac share a strained relationship, being explained by Isabel as "complicated", though she sees him as her friend. However, due to an unknown event caused by Isaac where someone got hurt, he has been cold and snappy towards the rest of the Activity Club ever since, though Isabel and Ed snap back with teasing. Though Isabel is willing to talk things out with him, she doesn't know what to say to him now because of his coldness towards her.
Isabel seems very friendly towards Suzy, even though it is apparent that Suzy has a harbouring grudge towards Isabel.
Isabel has only recently met Flipflop. She was at first confused about Flipflop's thematic incoherence, though she was shown to be impressed when he danced. She seems somewhat uncomfortable when he expresses that he doesn't want to be a burden for her.
Like all spectrals, Isabel has the power of ghost sight and interaction, meaning she can physically interact with those of the spiritual world where others cannot. Training under her grandfather, she practices and hones her ability to control her spectral energy and combines it with martial arts at an advanced level. She has been described by Mr. Spender as "the best fighter" in the Activity Club.
In Chapter Four, Isabel was seen sparring with one of her grandpa's disciples, and despite being years apart in experience and age, Isabel was able to hold against her own with the adult. In the first chapter, Isabel also was able to fend off against a grudge, a very volatile and dangerous spirit. It was likely she could have defeated it on her own if not for the intrusion of Max. She executioned inept skill in combat against both spectrals and spirits.
While using Eighfold's book as her tool, Isabel can control the seemingly endless supply of paper within her book and manipulate it into any shape or weapon she desires. She is also adept enough to control paper that is not in directly contact with the book, but any creation she makes cannot move independently of her. Her connection with Eightfold allows her an impressive range with the book, being able to connect with and use its powers from over twenty feet away.
She was later given an umbrella as a tool, which holds a turtle-like spirit called Flip Flop, who is very thematically incoherent. Flip Flop has the power to flip things.
|The Activity Club||The Consortium|
|Edward Burger | Isabel Guerra | Isaac O'Connor | Maxwell Puckett||Boss Leader | Cinnamon Stix | Agent Day | Agent Griggs | Francisco Guerra | Agent Savage | Greco Stucks | Texas Walker | Mina Zarei|
|Ms. Baxter | Vice Principal DuNacht | Mr. Garcia | Coach Oop | Mrs. McJohnson | Principal Pleezdoo | Mr. Puckett | Mrs. Puckett | Richard Spender | Mr. Starchman||Alex | Angry Band Kid | Ball Golem | Damien | Damien's sister | Dimitri Danger | Doghouse | Fitzgerald | Jeffavorite Flavors | Johnny Jhonny | Cody Jones | Lisa | Ollie Oop | Zoey Puckett | R.J. | Sam | Collin Sloinne | Stephen | Student Council | Susan | Violet|
|Spirits and Ghosts|
|Butterfly Ghost | Doctopi | Doorman | Eightfold | Flipflop | General Emerald | Forge | Ghost Train | Gorf | Hijack | Hissin' Pete | King C. | Lefty | Lucifer | Muse | Night Lamps | Nin | Patchworm | PJ | Queen of Kindness | Ravenous Gobbledygook | Scrapdragon | Sphinx of Games | The Shadow | Venus Guytrap | Vile Spirits|