The Last Guardian Facts, Backstory and more!

Here is my take on how the Nest came to be the way it is portrayed in the game!

Thanks for tuning in! If you enjoyed this clip, make sure to subscribe if you already haven't - this way you will receive even more entertaining content ;)
Some references:
Mastermind = Master of the valley
Marble tower = White tower

Twit here:   / mikishikishow  
Face here: https://goo.gl/iMC7L4

I finished the game a week ago and wanted to take a crack at all those mysteries that were presented in the game. So I am preparing a video with my theory on how this place came to be the way we see it now.

The Last Guardian is the third game by Fumito Ueda and just like the previous two games, the scene takes place in a big, uninhabited by humans and secluded from the world area and one of the main characters has or grows horns. It is an emotional rollercoaster that despite all of its bugs manages to deliver what it promises.
I will list all the major facts and I will use them to build a theory which would explain how the Nest came to be the way it is portrayed in the game.

FACTS
1. Judging by the sketches at the beginning of the game and Trico's look we can easily assume that this is a hybrid creature designed and created for some specific purpose. Most likely to guard something or an all around assault creature (it has lightning strike abilites (frikkin lazers!))
2. The barrels make the Trico's stronger and help them regenerate and heal themselves. This can be proved as you progress the game the lightning that comes out of the tail gets an OP boost and becomes a plasma shot. And if you have played the game I am sure you have been watching the horns of Trico pretty closely as you progressed. There is no arguing that the horns gradually regrow and even by the end of the game Tricos wings are fully healed. What's more is that the story is told in such a way that the player can not be sure that he originally has the ability to fly.
3. like Trico The ghostly guards have horns on their helmets, some have 1 or 2 but they are all used to control the guards and creatures, more on that will be revealed later in the clip.
The same stuff that's in the barrel is the one that engulfs the boy when he is transported while inside Trico, so the same substance used as nourishment is also used to preserve the cargo.
4. Have you wondered why the boy is covered in tattoos? Well we see that the tattoos on the boy appear after he is spat out. Before he was abducted he had no marks on him whatsoever. Due to in-game circumstances the boy is devoured and then spat back out by Trico. And after each consecutive cycle the markings multiply. At first it's subtle but by the end, a very big part of the boy's head is covered up by tattoos. We can say for sure that the tattoos are formed when the boy is inside Trico as some form of MARKING. And this plays out perfectly as a countermeasure if the chosen ones try to escape, for when the guards chant all the tats light up and the boy gets paralyzed.
5. The "eye" signs that we have to destroy in order to move forward and also used by the guards are meant to prevent the Tricos from going wherever they want. Tricos were originally programmed to stay clear of those signs. And those signs are usually placed in some pretty unstable places which can hardly support the creatures' weight.

6. The Marble tower was made to be really durable and unlike the rest of the buildings which are already collapsing, it doesn't show any signs of decay. So whomever made it was making sure that whatever was inside- would be well protected.

7. The mirror was designed to control the Tricos. However, at some point, the Master of the valley found a way to override the mirror's commands so that it control them (proof of that is at the clash scene of Tricos). There could have been other mirrors which the Master disposed of, but the Kid was lucky enough to find one in a burial chamber - which seems to be made of the same material the Marble tower is made out of.