Starfluid

There are currently only two fluids (more specifically, liquids) in the game;water and lava. That's all fine and dandy, but whereas the Nether has lava and the Overworld has water (as well as a few small increments of lava), the End has nothing. On top of that, there are no gases in the game. To solve these problems, I bring to you:Stardust.

Generation, Appearance, and Movement

Stardust generates anywhere in the outer end, either in small pockets, or in huge seas of Stardust, along with anything in between. Stardust has an animated texture, much like water or lava, but this one is of a sparkly substance slowly shifting between multiple colors, such as green and purple, to purple and yellow, to whatever comes next.

As for movement, Stardust doesn't spread like other fluids-it twists and contorts its way around the End, occasionally splitting. It rarely forms into various "constellations"-otherwise, just three dimensional shapes with different colors, such as an enderman's head or a pickaxe, as a sort of easter egg. It also has a few strange behaviors that are expanded on below.

Degeneration, and How Stardust Interacts with its Environment

What sets Stardust apart from other fluids (aside from its entirely different state of matter than anything else in the game) is Stardust's interaction with its environment and how said environment equally interacts with the Stardust.

Stardust often loses its luster-not metaphorically, either. As Stardust moves around, it loses a sort of durability which causes it to be visible less sparkly and outstanding. The larger the body of Stardust, the faster it degenerates. However, Stardust interacts with its environment to counteract this, using blocks that it generates called Crystallized Stardust and Moonstone.

One of the behaviors of Stardust is to surround sections of End islands, as well as whole (albeit very small) islands. When this is accomplished, it uses its highly corrosive substance to slowly spread across the section of Endstone and slowly eat away at any patches of the stuff still attached to a larger island or area. When this is accomplished, it sacrifices some of its mass and luster to crystallize the Endstone, using Crystallized Stardust.

Crystallized Stardust

Crystallized Stardust is a block, not unlike carpet, that spreads on top, on the sides of, and below a body of Endstone when naturally caused via Stardust. A section of Endstone surrounded by this block will slowly turn into Stardust itself, meaning there is more Stardust in the End than it began with. When the transformation is complete, the Crystallized Stardust starts to break apart and release the Stardust. This block is only harvestable when not surrounded on every side by other Crystallized Stardust, meaning you have a very small window of time when the new Stardust is released to get a few of this block. I have not thought of a use for it, though.

The original Stardust isn't completely unharmed, though. It is on the verge of "death" due to the strenuous process of creating more of itself.

Other Interactions with the Environment

Instead of taking away from the Environment, they also add to it naturally using three other blocks-Endstone, Moonstone, and the Star.

When moving around, the Stardust creates Crystallized Stardust clumps and takes away from its own mass, balancing the amount of the Stardust in the world due to the new Stardust being formed and the Stardust being changed. When these clumps of Crystallized Stardust break apart, they reveal Endstone and, more rarely, Stars (Additionally, the Stardust also forms Starbelts-credit to /u/Eyebolaids -when creating new Stars and Endstone).

Of course, Stars are new. So what do they do? Stars, in and of themselves, are rather unique light sources-they give the highest level of light, but they also have two other abilities;One, any Endstone in a vicinity gives off the light level of the Star, and passes it to other Endstone, which have a couple levels of light off of the original Star, and then that Endstone passes the light on, etc. Secondly, Stars send out new projectiles called Shooting Stars in random directions. If touched by one, the player continuously burns, but is also continuously pushed into the air by the Shooting Star.

Stars can only be mined by Efficiency 5 (5 is the highest level, right? Right?) diamond pickaxes, but they can also be crafted into Starstone building blocks, which are a bit less light-giving, but have the same light-passing ability that the Star has. Starstone also burns the player on contact.

Aside from just causing Starbelts, Stardust also crystallizes itself alongside larger end islands (or crystallizes itself in the shape of an end island) to increase the size/start a new End Island.

Moonstone

Earlier on, I mentioned Moonstone. So, what does it do, and how is it formed? Moonstone is formed in large spiky structures by very large Stardust pockets. Because of the sheer size of the spikes, the Stardust, which may have been huge at the time of creating the Moonstone, is now tiny, because Moonstone also requires multiple blocks worth of Stardust to form. Moonstone is a crystalline bluish material that serves an incredible use to dying Stardust pockets; When Stardust is dying, it goes over to the closes spike of Moonstone and uses a tractor beam-like system to bring a few Moonstone pieces up. When enough pieces are brought up, the Stardust regains its luster and often splits up afterwards. As for how it is useful to the player, I'm not sure, but it should have a magical purpose.

Stardust's reaction to the Player and other non-End entities

Stardust has a few unique properties regarding non End entities. First of all, it has a gravitational property that, although when outside of the pool of Stardust you are slightly pulled towards it (Not full on tornado-like, just a slight pull back that prevents you from jumping without being pulled back, moving forward without sprinting, or standing still without, well, being pulled pack), when you actually touch the Stardust the pull disappears. You can swim around on the outer edge of a body of Stardust, but as you get further inwards, you are increasingly pushed out. Upon entering the center of the gas, which is very difficult due to the pushing back, you reach a part of the gas which teleports you to a random body of Stardust in the world in the outer area.

Stardust also makes a conscience attempt to deter non-End mobs away, by shooting slow projectiles at them that don't do much damage, but do quite a bit of knockback.

And finally, the death of Stardust

What happens when Stardust loses all of its luster? Well, you're about to find out.

When Stardust loses all of its luster, it implodes upon itself and sends out 8 "barriers" (1 for each direction) that move forward and do multiple things. First of all, any Endermen and Endermites teleport away when they hit a barrier. However, many of them teleport away with a green or red blast. This is supposed to simulate how Endermen teleport across dimensions, but cannot get back. Secondly, Shulkers' shells break and they float off into space. These new Shulkers can rapidly fire projectiles that levitate the player downwards and prevent them from teleporting instead of the typical versions of the Shulker bullet. Thirdly, it obliterates most Endstone, but replaces it with a few Moonstone and Star blocks to simulate the Endstone just transforming. Finally, the barriers do nothing but damage non-End mobs and cause them to randomly teleport short distances like they are a Chorus fruit.

When the implosion is done, a Gravity Core block is left behind. These suck all non-End entities towards itself and cause said entities to orbit around itself. These can be mined to stop the orbiting, although you will be left with nothing but empty space below you, so it isn't recommended.

That was my Stardust idea. I hope you liked it, as it would add a lot to the End, in my opinion.

TL;DR:A new End fluid with many unnatural yet beautiful abilities and interactions.

https://www.reddit.com/r/minecraftsuggestions/comments/539hcb/starbeltsstar\_speckled\_asteroid\_belts\_picture/?