Hey fellow Nephalem! When facing bosses in Diablo III, it’s crucial to understand their mechanics. Adjust your skills and gear to counter their strengths. For optimizing gear, focus on critical hit chance/damage, cooldown reduction, and elemental damage bonuses. Don’t forget legendary/set items for powerful bonuses. Efficient leveling involves running Rifts or Bounties on higher difficulties for better XP and loot. Also, utilize Kanai’s Cube for extra bonuses. Good luck in Sanctuary!