Isabelle "Izzy" Lightwood is a Shadowhunter and lives in the New York Institute. She is rebellious and often dates Downworlders to get attention. She is sometimes standoffish, and has only recently begun to make female friends whom she does not see as competition. She is also very beautiful. Her cooking is often made fun of by Jace and Alec. Her signature weapon is an antique whip that she is quite skilled with. And though Isabelle looks tall and beautiful, she is a very dangerous foe. She loves fashion, as shown when she offered (and forced) Clary to wear clothes that she picked for Magnus's party. Yet despite this seemingly shallow and girlish side of her personality, she is shown to take things in her responsibility, shouldering the blame for her brother Max's death, despite being unconscious at the time. She is comforted by Simon, and Simon ends up sleeping with her (not sexually) in an attempt to calm her down. Then she casually dates Simon--who is also dating Maia at the same time--and finds out. She discovers that she may be in love with Simon, but won't admit it.
Clary Fray is incredibly stubborn and determined, much like her parents. Like all Shadowhunters, she possesses strength superior to that of an average human. Because of an experiment Valentine unintentionally performed on her before birth—infusing angel blood inside her as an unborn baby(through drinks containing angel blood which he gave her mother)—she also has the ability to create new runes and to amplify ordinary runes with her stele, giving them incredible power. Jace once called her "the hot-tempered redhead"
Magnus Bane is the High Warlock of Brooklyn. He was the warlock who signed the mind of Clary Fray after being asked to help erase her early memories by her mother. He first meets the other Shadowhunters at one of his Downworlder parties. He has Clary get him the Book of White, and agrees to help revive her mother with it. At one point, he says he is 800 years old, but Cassandra Clare said on her twitter he was actually born in 1640, making him roughly 367 when the Mortal Instruments books take place.
Sursa : Wikipedia.