The Two-Faced ring, and the way you get it off. You have to take it off the Other way, i.e you have to cut off the finger it was on.
The Hunter. Going around and killing people like animals. It's even called "hunting". His relentless efficiency mode.
The illustration of a Thing in Darke.
Some milder examples: Septimus's appearance Darke and Jenna's witchy clothing in Darke; DomDaniel melting down to a pool of slime in Flyte; Merrin Meredith being Consumed by DomDaniel in Magyk.
In Syren, there's The Book of Syren. Jenna and Beetle even describe it as being "like watching someone get murdered."
When a person dies, his or her ghost is as sane as the person in question was when they died. Think about that for a second. Imagine eternity if, when you died, you were completely, off-the-wall, crazy.
