"a dark reddish beard [...] straight-backed and keen-eyed. [...] He wore plain clothes, of a simple cut like those the Terrans wore" (The Heritage of Hastur, page 168).
Strong laran and greatly skilled technician during his youth (op. cit., page 172).
Kermiac has trained a lot of matrix technicians, including Desideria Storn in her youth (The Winds of Darkover).
He taught some simple tricks to his son and his wards (The Heritage of Hastur, page 172).