He seems to be wielding a damaged primal 2h sword and full primal armour. Because he only fights up close, he isn't as much of a threat as his two comrades. However, he can hit just as hard and quickly as his comrades (up to 1000 or higher if his level is high), and fast. He is immune to stuns and binds. Therefore, it is advisable to trap him behind one of his comrades instead (if they are still alive). This can be difficult if fighting in a group due to his tendency to frequently change targets.
Another strategy for team fighting would be to use Provoke on him and run around the room while your teammates take care of his comrades, but this can backfire if either of his comrades suddenly shift their aggressiveness towards you (though your teammates can use Provoke to shake them off of you), or if he suddenly starts pursuing one of your teammates. Running around the room can also deplete your run energy fairly quickly, so don't rely on it too often.