Intense Lucid Nightmare?

Hey all,
I just tried a WILD lucid dream last night and was successful and i was on the boardwalk in my city. I was testing cool attacks on buildings and people that i spawned, i tried and gave myself beast arms and punched buildings, and shot lightning down from the sky. It was like a normal dream, until i looked on the beach and saw a guy in a black short sleeve shirt and dark gray shorts, he was extremely pale and looked like a normal guy. So i decided to try my new attacks on him, i shot a lightning bolt at him and nothing happened, so i jumped off the boardwalk, gave myself beast arms and in one jump i got to him and punched him, nothing happened, so then the man grabbed my arms and slowly began to rip them off, he had me for at least a minute before he finally ripped them both off. I jumped up as high as i could now that he had no hold on me, i tried to repair my arms but i couldn't get them back, when i landed on the beach the man grabbed a hold of me again, but this time he started to crush my head with his hand, the hand was freezing, he had me like that for quite some time, then i shook him loose and tried to wiggle away, the dream ended with him shooting a light beam at me, i woke up before i got hit.

I was wondering if having a nightmare this vivid i common for lucid dreaming. (i am relatively new at it)
And i heard from a friend that it could be someone who entered my dream, can that really happen?

Having a vivid nightmare is common whether you lucid dream or not. Having any type of vivid dream is a common experience and need not be lucid.

Spending time thinking about your dreams is likely to make you pay more attention to any kind of dream you have and it follows that nightmares, lucid or not, will seem more vivid than before you started paying attention to your dreams.

If you were lucid and experiences like this crop up again you might try to remember that it is your dream and you can control the elements in it. Knowing that you can get away from such a man or that he's just made up is a way to control your dream content without succumbing to odd whims of the mind, particularly unpleasant ones that lead to you grappling to get away from someone.

As for someone entering your dream I couldn't answer that for you. Some people believe in that experience while others say that all the elements in your dream are created by your own mind and therefore not an intrusion by someone else. The truth probably lies somewhere in there and you need to decide that for yourself.

Whatever the case lucid dreaming is having awareness and ultimately control of your dreams. Make them yours!

Next time carry a mirror and shoot that light beam back at him! :)