this journal is for phillipa flint! she is a 94 slytherin who currently works writing for witch weekly, and just opened a burlesque/brothel called abditum in knockturn alley. [but no one knows she's the owner or affiliated in any way so shh] ANYWAY she was a prefect starting her fifth year so blaise would probably know her from that at least?
celia wood (theyoungestwood) is a 01 gryffindor and most commonly known for being oliver wood's sister - the youngest one. she was quidditch captain in school in her later years and now is training to be a medi-witch. i'm not sure if she and blaise would know each other.
gwenog jones (harpyqueen) is an 86 hufflepuff but is famous for being the captain of the holyhead harpies, and a member of the welsh national team. and occasionally being taken into custody after fighting people. because, um, passion. blaise would probably know of her if nothing else.
bill weasley (primus) is an 89 gryffindor and the oldest bro of the weasleys. you know, the cool one. no, not the one with the dragons, the other one. biggest difference for him with the premise is that he moved back to england after ginny had the whole possession thing happen. he works as an unspeakable at the department of mysteries so they may pass each other at the ministry or something?
xavier ansari (xxoxoxx) is a 94 hufflepuff who wouldn't really known for much remarkable until the past couple years. he's a muggleborn who worked in the muggle world after leaving hogwarts, but now he's the rhythm guitarist/backing vocalist in quake. they're kinda famous, so blaine might recognize him at least or something.