I never stop being surprised at people who study Aikido, they often say what technique they would use in a fight, your opponent creates ( you hope ) the opening for the application of a technique.
If you are involved in the said situation with a ``plan `` I can assure you that a stern look will not help you....
A good backward ukemi may serve you best.
Easy in the dojo where its comparatively safe and you already know the attack that's coming. Different kettle of fish when someone attacks you from behind using your head like a speed ball or punches/kicks your back in the kidney area or kicks your thigh for a dead leg...... Real attacks come from all sides in reality, so covering up and avoiding is the only option........ if you have the room to move!!......
Hard atemi first with immediate take down is the only real alternative...... Very similar to what you see in the cage, except you don't get a warning or the order to fight from the referee..... The only difference being is you don't stay on the deck if you can help it as that can be an opening for his oppos!!
It can be rough out there so avoid it at all costs if you can, stay aware, but be prepared to fight if you can't, either way your're bound to get a bit pasted, unless you are lucky and get the first one in.....