Diablo 4 Lord Zir boss guide - how to beat, location, and rewards

How do you beat Lord Zir in Diablo 4? Whether you're farming for strong items for the base classes or Vessel of Hatred's new Spiritborn class, taking on Lord Zir is a good plan. However, beating him is easier said than done.
The Diablo 4 Lord Zir boss was introduced back in Season 2, though he's still available as an endgame encounter, rewarding high-tier gear in the RPG game. Given how challenging Lord Zir can be, though, it's wise to enter as one of the best Diablo 4 classes in the meta right now, or even bring in one of the new Diablo 4 mercenaries to lend a hand.
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