At first glance, she seems much weaker than other Advent bosses, having merely 1,000,000 health and a large blindspot. That is until you realize her powerful gimmick and synergy with the enemies in her debut stage. First, her bigger piercing range and slow movement speed only prove annoyance with a guaranteed freeze posing a huge threat. Even with her much lower health, if she is killed by non-Zombie Killers, she can revive quickly and infinitely. What makes it all much worse is the fact that Z-Onel's debut stage includes two of them, making it arguably one of the hardest Advent Stages.