Lord Psiot VIII is the Faculty Head for Arcane Science – that covers the occult, magic, mysticism, etc. He was seen in his original outfit in his cameo during the Facuty Heads meeting on page 1.19… and what does he do? Obviously a bit of teleportation but as for the rest, stay tuned!
As for Hamish and Janice, they are third year wizard and witch respectively. Seen a number of times over the various chapters, But most recently starting from page 6.06, a sequence to which this entire exchange refers.