battle maniac; combat-crazed person
Describes someone who is obsessed with fighting and lives for the thrill of combat. Often used in fiction, games, or to describe a person with an extreme love of battle.
He's a battle maniac, and apparently he can't stand days without a fight.
The character in that game is portrayed as a combat-crazed person.
Compound of 戦闘 (sentō, 'battle') and 狂 (kyō, 'madness' or 'fanatic'). The exact historical derivation is uncertain, but the word follows a common pattern for describing an enthusiast or fanatic.