English vs Spanish : Be There or Beware

One of the things about English is that sometimes it is able to express ideas that would require a  more complex structure in order to be said if we are using Spanish and perhaps other languages as well. 

To make my point I have picked these words"Be there or Beware" which is a funny way to warn others about not attending a certain event. Funny and everything there is one problem with this phrase: how do you put it into Spanish? I have come up with the following version: "Es mejor que vayas o atente a las consecuencias" 

Obviously, the fact that is difficult to say it in exactly the same number of words as in English demonstrates that English has the "upper hand" here. And the real problem is that in Spanish since we never say something like: "Esté ahí o tema" and is even worse when we talk to a friend and we then "tuteamos" such person. That would imply saying something like "Estate ahí o Teme." We would prefer: "Ve allá o sino..." 

As you can see this is not easy necessarily. Surely there is more to say, but then again  that is part of learning a language: do some research yourself .