Cool gamertag suffixes / prefixes?

I would like to rename myself on the Xbox to something with "Shadow". However, most of it is already taken, so I wanted to ask if you know of any cool suffixes / prefixes that I could add.

What do you like to gamble? Perhaps it can be related.

XXShadowPvPeZxdXx

The good old kiddie names

Can't you think of anything more original?

It often sounds childish otherwise.