Soul seeker mob (Nether)

Imagine wondering the soul sand valley while looking for the nether fortress until you see it. A blue glow that's slowly moves towards you. Then it starts to attack. This is a mob i call the soul seeker. Soul seekers resemble an endermen but skeletal and its slightly shorter. The soul seeker has a blue glow in its ribcage (the soul) and it is hostile. The soul seekers attack include being bit or punched by it. The only way to attack the soul seeker is to attack the soul. But it isn't that easy to attack the soul. You only have a small window of time to attack it and thats when its about to attack you. Its ribcage exposes its soul which you can then attack. After defeating it it drops its soul. The soul adds a new crafting recipe called the soul core crafted by the soul in the middle of the crafting table and 4 soul sand blocks surrounding it. When the soul core is placed you can walk on soul sand without being slowed down for 15 blocks in all directions.