Speaking of or Speak of the Devil

[Ninaleeing]

Hello friends,
Recently I have a problem with the way we say "Speak of the devil!"

Besides "Talk of the Devil, and he is bound to appear," may I say
"Speaking of the Devil, and he is bound to appear." Or
"Speaking of the devil and the devil comes." Or
"Speak of the devil and the devil comes." Or
"Speaking of the devil, and here he is." Or
"Speak of the devil, and here he is." Or
"Speak of the Devil! Look who is here."
In this case, should "d" in the word "devil" be a capital letter?

Please help me with the above sentences.

[Josef]

We wouldn't normally use -ing in these cases.

Talk of the Devil, and he is bound to appear

In Christian and Jewish belief "the" Devil is the chief evil spirit, also called Satan, and usually merits a capital D.

If you use "devil" to simply refer to any evil spirit, it does not get a capital D.

[Ninaleeing]

Dear Josef,

Thanks so much for your help.