Withercraft

This allows you to turn in a powerful, advanced boss, giving you awesome abilities :

• flying
• go extremely fast
• avoid fall damage
• fire explosive wither skulls
• etc!

Of course, all the previous features are still working :

• wither skeletons spawn at night like any hostile mobs : killing them will sometimes give you a wither skull.
• craft 4 soul sand with dirt
• create a basic golem pattern
• hit the middle-top block of the pattern with the 3 wither skulls stacked
• The wither boss spawns!!