Boss is fairly simple, he has a shield phase where he recovers HP , not sure if hitting the boss does anything during that time, but it seems to always heal him for about 3 HP bars. Otherwise enjoy the free loot

Does anyone know the iLvL and Quest Requirement to be able to deal damage on it?

The boss has a buff when he shields that heals 1% of his total hp every 2 seconds and also reduces all dmg taken from physical and magical. Mouse over the green body under his HP bar when he shields to read the buff. Damaging him during this phase will NOT heal him. Just don't waste your skills during this phase and only auto attack him. Rovlen in West Luterra has the same mechanic. I don't know where this lie that hitting him during the shield phase heals him came from but it has spread everywhere. Correct people if you see them propagating this lie.