Blue crystal

And also, there's no need to mislead people about seraphs.

I don't understand why you're being rude to the map author, especially when you don't understand the issue. Seraphs have one ability - warlock. Among their spells are "Divine Retribution" and "Wrath." They do not possess the "drain life" property.
I remember there was some scenario mod in which seraphs actually had vampirism. So, using your terminology, there's no need to mislead...:rolleyes: