You can direct it wherever I suppose.
But unlesse you're an edo(or if you have susanoo), the destructive power of the technique would destroy you within it, because the range of the destruction of the atack should be huge, damn huge. It appears that you can only make it appear in an area in which you are present. You wouldn't be able to escape it.
So, if I was an edo or if I had susanoo, I would pick tengai shinsei. I would have to be very skilled with susanoo, because makybe the atack would crush my susanoo too. If none of the above, I would choose chibaku tensei.