I agree with a lot of Vel and Moonlights desriptions.
i experience Ni running amok like an almost altered state of consciousness, or perhaps it really is an altered state.
A series of jumbled images in super fast succession, meaningless, too fast to join the dots or make connections,..a feeling on non extisence..being cast adrift grom everything you thought you knew, all reference points gone..like drifting in infinite space with no star map..nothing to tell you where or 'when' you are. The scarey nothingness Vel seemed to speak of. Theres a feeling of loss of identity,. when Ni is running amok,.. 'I' doesnt exist for me... I am formless shapeless,.. just floating amongst Ni forms and shapes and symbols, I am nothing, I am no one, I do not really exist, thats how it feels. The persona that is 'Me' is a facade, stripped away. Everything seems pointless,.. everything is meaningless. Too many possibilties and ways to perceive, so that it ends up a scrambed meaningless jumble.
The other side of Ni running amok is a little more focused for me..this is when future prediction becomes easy,.. i can actually talk about it as i see the myriad possibilities for the future being pared down into one path, the most likely outcome.
Past present and future all exist simultaneously and you can cherry pick a point in time, and say whats going to occur, or what did occur.
Almost like meditative or trance states.. without the hallucinogens
Coming back to 'reality can be jarring and depressing.
The other Ni world seems more real to me these days, but i suspect thats because ive let my NI grow to silly proportions.
Still, its 'interesting' in that it is how I run, my brain uses Ni so naturally, its just when its on hyperdrive for some reason, it becomes overwhelming..its not just images, its emotions, feelings, thoughts..(great big thoughts,..genius thoughts that I cant quite grasp hold of,.. thoughts that are just beyond my reach, a quick taste of understanding and comprehension,.. and then gone) Its certainly like a trip, and you dont always feel in control.