loner
lone wolf
lone hand

If we were dealing with the Mask as a lone hand, it might be better to hold them.

He plays a lone hand, keeps pretty much to himself.

"Don't try to play a lone hand or it will be the worse for you."

So far I had played a lone hand and rather enjoyed it.

Because he's a man who likes playing a lone hand.

You understand now why I can no longer play a lone hand.

In playing a lone hand it is always a great advantage to have the lead.

"Because, as I say, she wanted to play a lone hand."

He preferred to play a lone hand for the present, keeping himself in the background.

Over the long term, therefore, America must play a lone hand.