The screen then goes black after he recites the message again, and he speaks directly to the audience. "Darkiplier" started as a much darker version of Markiplier, who often behaved in a scary fashion in order to garner reactions from the audience, especially made effective in videos that are already horrific in nature.
As time passed, the fan base considered "Darkiplier" to be a separate being from Mark, making varied appearances in several of Mark's videos, and occasionally interrupting a recording with a foreboding message to the audience.
It is revealed that Darkiplier is actually a fusion of Damien, his sister Celine, the body of the Protagonist (the viewer), and the Evil Entity that was held inside the House for decades (characters from the series).
The series started when Mark, out of jealousy for the Colonel's love affair with Celine (his ex), planned to frame the Colonel for his “death” by a game of Russian Roulette, tricking him into thinking he wanted to mend their broken friendship but in reality the Manor itself is a character all it’s own and not only does no one stays dead within it, the longer they stay within the Manor the worst that person’s sanity gets.
There have only been a few instances of such behavior, but each instance has ranged from very subtle and effective to very obvious and amusing.