controller vs overcomer

controller and overcomer both are nouns.

Word	Noun	Adjective	Verb	Adverb
controller	Yes	No	No	No
overcomer	Yes	No	No	No

As nouns, overcomer is a hyponym of controller; that is, overcomer is a word with a more specific, narrower meaning than controller:

controller: a person who directs and restrains
overcomer: someone who overcomes and establishes ascendancy and control by force or persuasion

Other hyponyms of controller include nazi, subduer, surmounter, suppresser, suppressor, withholder.

controller (noun)	overcomer (noun)
a mechanism that controls the operation of a machine	someone who overcomes and establishes ascendancy and control by force or persuasion
someone who maintains and audits business accounts
a person who directs and restrains