Shade mob

New mob. What if there was another mob to spawn in the deep dark with the warden, but more commonly. The Shade would be a completely black mob with white eyes and black particles emitting from it, it would have 18 health and do 3 damage, however, when it hits someone its inflict a random debuff from level 1-3 for 1-3 seconds. it would have a chance to drop  cursed essence, which can be thrown and it does the same thing as the shades attack, but it can be smelted into purified essence, which can be eaten and gives a random buff for 1-3 seconds on level 1-3 when eaten.