The fact that Laura had to constantly move across the country to avoid Satan and protect Chrissy from his clutches. It's frightening to consider just how their relationship deteriorated to such a point.
While Satan is presented as a fun-loving, chill guy, he's still very much... well, Satan! He is unafraid to manipulate, threaten, torture, or kill any one to get what he wants, or just for his own amusement. Including his own daughter, even though he does grow to genuinely care about her.
When Chrissy's Antichrist powers first activate; as the bullies laugh at her embarrassing first period, her eyes darken to an inky black, everything around her starts shaking and shattering, her body starts contorting and her tormentors start to blow up and pop like balloons with their blood, guts and limbs splattering everywhere. It's but a taste of what Chrissy and her satanic magic are capable of.
