Dark Ghost

Dark Ghost is the 3rd boss in the game that appears around wave 31. It uses 3 special abilities:
 * Bloody Souls - Red Orbs that fire around the boss. Deal slight damage to players.
 * The Shockwave of the Dead - Earthquake that moves inwards toward the boss instead of outwards. It knocks down players.
 * Dark Soul - The boss becomes invisible for some time. When it reappears it shoots out a wave of Bloody Souls in all directions or uses The Shockwave of the Dead.

Tips

 * It is not recommended to use sniper type weapons if the boss is invisible.
 * It is recommended to be near the boss but not too near for its Inverse Shockwave attack.
 * It is recommended to get to a high place when it does its Inverse Shockwave attack, as it protects you from damage and gives you more time to attack.

Trivia

 * It is the only boss that can turn invisible.
 * Dark Ghost was added during V2.
 * This boss can glitch sometimes, like after you killed it, the boss will remain standing for a long time before it collapses and disappear.