Why do the Lucent Gems know so much about the Crystal Gems? Because they have broadcasted their stories across the cosmos. But instead of inspiring hope, it created rage.
The Final Boss of the overall series is a fusion between three Gems from the courts of White, Yellow and Blue Diamond, making this the closest to an epic fight against all three Diamonds.
The fusion of Lapis Lazuli and Peridot is Turquoise. They are both artists and Turquoise is the name of not only a type of gem but also a type of color.
Anyolite having Pyrokinesis might be a reference to the fact that Anyolites are Zosites with Ruby inclusions. And as we know from the original series, Rubies have fire powers.
In the Bad Future sequence from "Enemy of my Enemy", it's stated that after Black Rutile defeated the Crystal Gems in that future, she popped the Cluster's bubble and essentially destroyed the Earth. Given how many humans have been introduced since this chapter, they're all Killed Off for Real before they could even debut.
Likewise, it is shown that if the Gems had failed to pacify Steven when he was a monster in time, then he would ravage the Earth and wipe out all existing life. But how long did that take?
If the Universal Lords own every other planet in the galaxy, then dos that mean every living thing in the universe is essentially enslaved?
for Part 4 implies Jasper and Black Rutile are a little similar. One hasn't let go of the past, the other wants a future that only she appreciates.