The goal was to win without requiring extremely high stats.
2 Guardian Summoner + TB Monk + Ranged DPS Hero
Harbinger won't try to get ahead of the Core or Ogre Minions. By taking advantage of this, you can focus on the boss fight.
If you feel the aura's range is insufficient, reduce LT and place aura in two locations. However, placing it too close to the core risks being targeted by Djinn.
Ideally, TB Monk should use weapons without knockback to eliminate the risk of unintentionally moving Harbinger.