intercessor vs mediator

intercessor and mediator both are nouns.

Word	Noun	Adjective	Verb	Adverb
intercessor	Yes	No	No	No
mediator	Yes	No	No	No

As nouns, intercessor and mediator are synonyms defined as:

intercessor and mediator: a negotiator who acts as a link between parties

Other synonyms of intercessor include go-between, intermediary, intermediator.

intercessor (noun)	mediator (noun)
a negotiator who acts as a link between parties	a negotiator who acts as a link between parties