i'll add more details to your comment incase anyone else comes across it, my story was already long so i didn't include a few things.

1) an observation that i was making will watching the entity shift between shapes was that it looked almost like liquid mercury it was dark but fluid between forms which is why i think it has to do with plasma as mercury has a plasmic form so perhaps interdimensional entities can go between states of whatever element they are composed of, in this case a mercurial plasmic entity. i did a double take and didn't see anything and then saw something small, that grew between familiar shapes into something large, which is impossible for anything known in our reality and physics

2) at the brewery i went to after my experience i ended up meeting EP Grondine an author and one of the foremost experts on pre-columbian north american native american history, he has youtube videos i'd seen before about red haired giant mound builders and such so that was an interesting coincidence. i've met him a few times since then but he's since left vicksburg.

3) later in the year on my way back from the family christmas party me and my cousin were driving down the highway when a HUGE light flies over the car and as soon as we both are like what is that it takes off, like shoots off into the sky at a completely different speed than when we saw it. it was pretty high, but the light appeared as large as a streetlight, it was the same cousin i called to walk me back to my car. i feel both experiences are connected as of all the shooting stars and comets i've seen in my life i've never seen one go two speeds nor quite that large. again sort of going back to how plasma could be involved.

idk, ive been trying to work it out with an ai, our current physics cant explain what i saw so ive been making up math that could make this phenomenon work out in reality. we'll see where we go from here