Calvin is a well spoken teenager, and within the first few minutes of meeting him, people can usually tell that he's well read and academically gifted. If they spend any more time with him, though, and happen to see Calvin under stress, they might realise a few other things too. Despite being good with words, Calvin's not very composed. He constantly sounds like he's barely holding it together, whether he's about to slip into existential ennui, or just have a breakdown. The former is fairly likely, the latter not so much. He does get nervous a lot, and tends to babble when he's flustered or scared, but he's a little too steely to let anyone see him actually crack.

But one of his biggest problems is that Calvin has a bad attitude. When he's faced with a problem, he's whiny, and needs to vent for several minutes before he actually starts solving it. Because of his negative outlook, Calvin's his own worst enemy, making all his problems bigger than they need to be. Calvin assumes the worst of people, and creates detailed narratives in his head about why they're doing what they're doing based on very little evidence. Usually the theme is that everyone hates him, or they're silently judging him, or they're doing this thing he dislikes specifically to spite him. The truth is that a lot of people just don't notice or care about Calvin. If they do actually dislike him, it's probably because he makes himself so difficult to love.

Calvin is a big talker, which means two things: First off, he can be very diplomatic. Calvin is never without something to say, and a lot of the time can figure out exactly what people need to hear to feel better. He's exceptionally reassuring, and always has some excuse. He's good at framing himself as reasonable, which is a problem when it comes to talking down his gloomy fantasies or picking out his half-truths. When threatened, he shifts blame so that Calvin and the people he likes are never in the wrong. This means Calvin is not a great friend to talk to when you need a reality check, but he'll always be there to validate your hurt feelings.

The other, much worse, side of this is that when Calvin fights, he gets mean. He goes for the (verbal) jugular right out of the gate, quickly escalating arguments that he should have let go. An angry Calvin is sharp, condescending, dismissive and mocking. He'll say whatever he thinks will hurt the most. Of course, he usually regrets it right afterwards. Sometimes it's out of guilt, but it's more likely because if the fight ever leaves the realm of talk, he's in trouble. Calvin's ultimately a bit of a coward, and will try to weasel his way out of the consequences after lashing out.

Nasty temper notwithstanding, Calvin was always submissive to his bully of a roommate back at Hogwarts, Sam Goyle. Goyle used his size and more aggressive nature to both dominate and protect Calvin, creating an unfortunate codependent friendship. Calvin did whatever he said, and was always on call to try and get him out of trouble. But Calvin's pushover tendencies hide a steel core that can be brought out when Calvin is pushed far enough. When he's irritated, Calvin is appallingly stubborn and petty. When he's comfortable with you, he's also appallingly stubborn and petty, so Goyle often got a double dose of this charming behaviour. Calvin's deceptively bossy by way of diplomacy, and tries to talk everyone around him into doing things his way. Luckily, Calvin's way is just to get on with it. He ushers friends to quick, simple solutions, and has no time for bullshit (unless it's his own).

When he's relaxed, Calvin opens up into someone surprisingly gentle and cautious. He can be coerced into friendly teasing, and is endearingly naive about a lot of things. Doing anything ironically is totally beyond him. He has a dry sense of humor, and enjoys friendly verbal sparring, even at his own expense. There's a bit of uncertainty and shyness to his relationships now, since his social life is so wildly different from what it used to be. The change has been a lot to deal with, and maybe he's a little humbled, but mostly he's just despondent. His dreams of being on the top again, but this time without being bossed around, are done for. He hated Goyle, but now that Calvin's unprotected and sitting the bottom of the pecking order, he often wonders if he was short-sighted to run away from that. But he has to admit, having friends he doesn't secretly resent and fear is novel.

Calvin disliked having to be cruel, but he was too cowardly to fight back. At least, that was always his excuse. Calvin is perfectly capable of being mean without anyone’s guidance, which makes him a bit of a hypocrite when reflecting upon his past behaviour. He feels bad and thinks he's "above" treating people like that, but he misses how it made him untouchable. Despite all of this, he'll usually ends up doing the right thing if he has an opportunity, which gave teachers hope that there was a kind soul somewhere in there. It takes Calvin a long time to take responsibility and apologise, but if you’re patient, he'll get there. At the end of the line, when left to his own devices, Calvin pulls through.

tl;dr
+ diplomatic, articulate
+ academically gifted
+ reassuring, ready to validate his friends' feelings, right or wrong
+ will end up doing the right thing... eventually
= socially uncertain, and having a difficult time with it
= naive
= conflicting feelings about former role as a bully
- verbally cruel and condescending when angry
- secretly stubborn
- uses diplomacy to shift blame and justify his bad decisons
- pessimistic and whiny with a perpetual bad attitude
- draws conclusions about people based on very little information

⇢ Angelica Evercreech (nee Avery), mother. Pureblood. Personal assistant to a successful wizard fashion designer. Angie is often stressed out, and finds extended family get-togethers exacerbate that. No one on her side was thrilled she married Morris, and Morris' family is just put out he exists at all.
⇢ Morris Evercreech, father. Halfblood. Morris is an aspiring painter who doubles as a stay-at-home dad. Now that all his boys are in school, he has a lot more time to get work done. Morris' grandmother ran off with the halfblood Emery Evercreech, creating the Evercreech offshoot of the Bulstrode line. As a result, his relationship with the Bulstrodes can be strained.

⇢ Damon Evercreech, eldest brother. Senior Coppertale, former Gryffindor. Calvin idolizes and adores Damon. They're uncommonly close.
⇢ Edmund Evercreech, older brother. 6th year Gryffindor. Eternally in trouble. Edmund is brash, and gets into fights on a weekly basis. In many ways, he's the worst kind of Gryffindor.
⇢ Nathaniel Evercreech, younger brother. 3rd year Gryffindor. Always in trouble. Nate's disregard for authority landed him in Gryffindor.
⇢ Rupert Evercreech, youngest brother. 2nd year Slytherin. Constantly in trouble. Rupert is a snotty boy with a love of pranks.

Teachers at Hogwarts dread the Evercreech boys. Not one of them has ever been pleasant or easy. Calvin, right in the middle, was considered the best of a terrible bunch, but that was hardly meant as a compliment.

Calvin's brothers were all disastrous from the start. They fought, they lied, they were mean, and they were arriving at school one after another with no reprieve. Calvin had his fair share of troubling behaviour, but next to Edmund's fights, or Rupert's pranks and Nate's blatant rule breaking, well, it just wasn't as big of a deal, especially to his parents. Calvin was clever enough to keep his misbehaviour out of their sight, and therefore, he was an angel in their eyes. His parents always praised him for being the good child, the easy child, the one they could rely on to be responsible. If his brothers said otherwise, they assumed it was petty sibling rivalry.

The first year of Hogwarts, for better or worse, Calvin had found a fast friend in Samuel Goyle, his new roommate. Samuel was a lot of what Calvin wasn't: strong, direct, and sure to grow up classically good looking. Unfortunately, Sam didn't treat anyone, including Calvin, very well. The two of them became the leader (Sam) and the number two (Calvin) of a group of bullies notorious for being particularly mean. Calvin's role was to get the group out of trouble and smooth things over with the professors, although he said his share of awful things to their targets, too. By the time they were in third year, Sam and Calvin had a contentious friendship, full of competition and jealousy. Sam knew he was in charge, but envied Calvin's marks and the ease with which he navigated conversations. Calvin resented Sam for walking all over him, but never stood up to him or stopped him from mistreating their classmates. They both secretly believed the other would be nothing without them, and they were inseparable for all the wrong reasons.

Meanwhile, Calvin's parents never believed he was capable of hurting a fly. He was, after all, their one well behaved child. All his brothers constantly needed punishment, intervention, and oversight, but not Calvin. What Calvin lost in attention, though, he gained in privileges. Larger monetary allowances were a common reward/apology, as was permission to go out late at night on holidays. All attempts by teachers to tell his parents that Calvin was as much of a problem as his siblings fell on deaf ears.

It was an especially hard to convince them because Calvin's marks in school were impeccable. Calvin was a brilliant student who took as many classes as he was allowed, and worked hard to master all of them. It was difficult for the Head of Slytherin to watch Calvin be so promising, while also enabling Sam Goyle to the degree that he did. Whether the professor's plan was to break up this little group of bullies, or to save Calvin from becoming any worse, he brought up the Gooseberry transfer program. It immediately appealed to Calvin because of its prestige, and it seemed like a perfect way to show up Goyle, get away from him, and impress his parents even more.

During Calvin's first year at Gooseberry, he thought he could arrive on the scene and rule this stupid American school. Instead, he was quickly knocked down a few pegs, finding that there were plenty of students bigger, stronger, and cooler than he was. There were dozens of brilliant witches and wizards, and he was no longer special in any particular way. He realised without the muscle or the looks to back up his authority, he couldn't do what Sam did. By the end of his humiliating freshman year, Calvin was beginning to accept that he really was nothing with Sam.

And yet, his pride wouldn't allow him to admit that. He returned to England with tales of how much he loved it in America, and how popular he was. The only person at home who knew better was his brother, [Damon?].