Wretched Wraith boss for mountain temple

The caves and cliffs update will change 2 things; the caves and the mountains. That is why I see it fitting for there to be a new structure in the mountains, a reason to want to climb those high peaks other than goats. I propose that the new structure is a mountain temple(Name is changeable). If you want to learn about how the dangerous climb to the peak would work, click on this link. Once you reach the peak, you would be able to enter the temple. To learn about what would be inside the temple, click here. In the temple, your main objective would be to reach the boss room. Once you reach the boss room, you would immediatly get the full chill effect, with the new particles around your screen and all, unless you are wearing leather armor. In the middle of the room, a wretched wraith(which is a mob from minecraft dungeons) would spawn. This would be a boss type mob, with a boss health bar. It would have the same behavior as in minecraft dungeons, and defeating it would give you a good amount of levels. Once you defeat the boss, a door would appear, leading to a chest room. There would be 2 chests. Some ideas that I have for loot are diamonds, emeralds, leather armor, and 2 new enchanting books.  1 would be the warmth enchantment. There would be 3 levels of warmth, and each level would slow down the time it takes to take damage from the cold. A full set of warmth 1 armor, or 2 pieces of warmth 2 armor, or 1 piece of warmth 3 armor would keep you from freezing entirely.