Pronunciation (it may surprise you):
http://www.pronouncenames.com/pronounce/joachimHistory:
Born and raised on the streets, Joachim was no stranger to the tricks of the criminal trade. Relying on others charity for several years while he was alone with little to show for it, he came to accept his philosophy that everything had to be taken if you want it and you only deserved what you were skilled enough to take.
This view of the world became quite advantageous during his years as a street criminal. He applied his talents as a thief, conman, and many other petty crimes that kept him alive.
One day as he was running from the police, he came across Topher Noir where he accidentally got him involved in the chase. Despite this, Topher helped the pair escape custody.
Grateful and impressed by Topher's skills for survival and his eyes, he offered to take him under his wing. Topher accepted and after awhile, the two became, as the saying goes, 'thick as thieves'. Joachim acted as the team's manager , sniffing out new opportunities for them to make a quick buck and planning it out. Topher was often the point-man, executing on Joachim's schemes and the profits were split down the middle.
However this partnership hadn't lasted as long as either of them wished. Topher, fearing he would hurt his best friend with his eyes, left the team to continue his self imposed exile. But this never stopped the two from meeting up.
Upon arriving at Hogwarts, Joachim took an immediate fixation on his old partner's girlfriend. After betraying his friend to attempt to steal her, the two had a massive falling out that they have only now started making repairs to.
Personality:
It isn't difficult to imagine Joachim growing up on the streets. He has a very 'every man for himself' view of the world. He's very vulgar and crude, often speaking taboo in common conversation. He also has a severe distaste for 'rich snoots', due to their ignoring him when he was a beggar.
This isn't to say he's completely lost to good qualities. Often he'll try to cheer his friends up with a party and he does care for people. He'll even (albeit begrudgingly in some cases) go out of his way to help them.
He's not very academically intelligent, opting to use street smarts and skills to solve his problems instead. Like Topher, he uses his skills as a thief for the betterment of his selected cause. But UNLIKE Topher, his selected cause is the side that benefits him more at the moment. He could just as easily help evil as help good, it's all dependent on circumstance.
As well, he's exceptionally greedy. Often times the prospect of higher pay will be enough to motivate him to do whatever the buyer wants of him.
He has a very addictive personality. He drinks frequently and even smokes a pipe on occasions of high stress. As well, he's completely obsessed with 'dames' and believes himself to be irresistible. However his insistent flirting often has the opposite effect.
He does have trouble staying loyal to the people he loves though, having betrayed both his best friend and girlfriend a couple of times with minimal hesitation. It can be argued that he is still breaking his street habits for this though.