1) Accusatorial 2) Accuser 3) Arguer 4) Caviler 5) Caviller 6) Combatant 7) Contester 8) Controversialist 9) Crusader 10) Debater 11) Hairsplitter 12) Logomach 13) Logomachist 14) Meliorist 15) Obstructer 16) Obstructionist 17) Obstructor 18) Quarreler 19) Quarreller 20) Quibbler 21) Reformer 22) Resister 1) Argumentative one 2) Controversialist 3) Debater 4) Eristic 5) Human 6) Individual 7) Mortal 8) Person 9) Somebody 10) Someone 11) Soul 
• (n.) One who disputes; one who argues // opposition to another; one appointed to dispute; a controvertist; a reasoner in opposition. • (v. i.) Disputing; engaged in controversy.
Dis'pu·tant adjective [ Latin disputants , present participle of disputare : confer French disputant . See Dispute , intransitive verb ] Disputing; engaged in controversy. Milton. 
[n] - a person who disputes
disputant 1. Someone who is good at, or who enjoys controversy. 2. Anyone who is involved in an argument or a legal dispute. 3. A person who disputes; a debater.
controversialist noun a person who disputes; who is good at or enjoys controversy
a person who disputes; debater.