Because there is a connection between the Dark Lord's mind and your own. Whether he is as yet aware of this connection is for the moment, unclear. Pray he remains ignorant.

Hey, enough chit chat. We need to concentrate here. Feeling a little agitated, Magnus? Don't make me laugh, dark Lord. Now put on some pants and fight like a man.

I am the lord of darkness

Lord Of The Ring

Nazgûl

Praying to the Dark Lord who wished our enslavement,

Sauron

SNAPE: No! He belongs to the Dark Lord.

Yes o mighty evil one

1a. Sauron was destroyed...