cian in 18 words:
musician magician electrician
physician politician statistician
mathematician logician arithmetician
optician pediatrician obstetrician
patrician technician theoretician
beautician dietician cosmetician
sion in 47 words:
expression impression oppression
depression repression progression
suppression regression aggression
egression congressional recession
procession succession accession
excision obsession confession
profession obsession possession
discussion concussion passion
compassion percussion session
concession mission admission
intermission transmission emission
remission commission commissioner
permission tension intension
extension pretension apprehension
comprehension pension dimension
mansion expansion
Exceptions:
suspicion complexion ocean