I like it!
Just the way you examine his personality and the little joys he would derive from certain things i.e. making the temperature cold in the hallway. In addition, I enjoyed the hazy introspection in regard to his relations the Lily, Harry and Albus in life.
This bit:He must have been a terrifying sight in life. That thought also pleased him immeasurably. was quite charming and very, very Severus.