Lucid Dreaming in Blackness with No Body

Last night, I attempted to MILD a lucid dream. I fell asleep saying the mantra, "I will be aware" over and over again. When i was dreaming, i saw different shades of gray and i thought, "I'm dreaming!" I didn't do any reality check or anything, i just thought it and could tell the difference between dreaming and reality. But i continued to see the different shades of gray and nothing appeared. I was stuck in darkness and i didn't have a body when suddenly the dream faded. I moved on to a dream where i was non-lucid. I didn't try to visualize any dream while i was there. Just can anyone tell me why this happened? Thanks

Odd dream?

If I understand your mean correct, you were in dark place with nothing. It is natural in lucid dreaming.
here is a suggest to do:
When you see you are in darkness you can look at front of your hand. it can be useful really. after you went out of darkness you should make your dream world stable. To do this you can sometimes spine around your self or solve a simple mathematical question like 12*2=24 (depend on your level of mathematics)
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And about when you became non-lucid I must say It can be control too. you should be aware when you are lucid that false awakenings can be occur and as I said spine around yourself and solve math to make your dream stable. ;)