sympathiser vs communicator

sympathiser and communicator both are nouns.

Word	Noun	Adjective	Verb	Adverb
sympathiser	Yes	No	No	No
communicator	Yes	No	No	No

As nouns, communicator is a hypernym of sympathiser; that is, communicator is a word with a broader meaning than sympathiser:

sympathiser (noun)	communicator (noun)
someone who shares your feelings or opinions and hopes that you will be successful	a person who communicates with others
a person who commiserates with someone who has had misfortune