Updated with many bug fixes. Mechanics change.

Ghast boss now requires pylong destruction. Also If no zombies are in the
arena the player will be stricken with wither. New mechanics require players to
maintain a positive zombie count.

Zombies in light house encountr now move at speed of 0.5. Very quick, requires
knockback. Serntz now is a zombie, and moves at a speed of 0.6. Quick fast, and
has a knockback weapon. May change.