When Xerath dies his body quickly becomes unstable and overly shiny, just to blow up a moment later, much like a nuclear-powered machine.
The icon for Xerath's ability, Arcanopulse is slightly similar to that of the mastery Blast.
Xerath's dance is known as "industrial dancing", which is evident in the song Pong by Eisenfunk. A comparison can be seen here.
Xerath himself can be seen when he performs his taunt. As he disarms the parts of his sarcophagus, a person made of pure energy or electricity can be briefly seen.
When he dies this "person" disappears, what remains on the ground are the shattered remains of his sarcophagus.
Xerath's ethereal form imprisoned in a human-shapen sarcophagus parallels Battle Realms' Master Warlock, consisting of an ethereal warlock inside another warlock's skeletal remains.
It's likely that that form was his actual look before he got locked away.
Some speculate that Xerath is ambidextrous as he uses both left and right hands for different attacks and abilities, unlike most champions who almost always use their dominant hand (usually their right one).
Xerath's appearance may be a reference to Starcraft'sArchons, which are also beings of pure energy.
Xerath means "one who shares" in Ancient Shuriman.
Xerath is one of several entities presented as (nearly) omnipotent in the League of Legends universe.
Syndra has been speculated to be or have the potential to become godlike, much like Xerath.
However much like Syndra, he is severely limited at the moment.
Bard is potentially more powerful than Xerath, a being seemingly outside regular time and space. However, he does not show off his power as much as Xerath does.
Xerath's new lore shares some similarities with Kefka Pallazzo from Final Fantasy 6/3. They have both deceived an emperor to become a greater magical being.
Considering similarities between Azir's lore and the Egyptian god Osiris, Xerath's mythological inspiration would be Set, who likewise betrayed and killed Osiris.
Xerath's lore is inconsistent about how Xerath first met Azir:
Xerath's and Azir's main lore related clearly that they both first met in Nasus' Great Library.
Yet Unbound implied that Xerath first met Azir sinking down in quicksand and rescued the latter.
Still, Xerath rescuing Azir in Unbound might happen after their mutual encounter in the Great Library.
From Xerath's perspective, he was punishing an injustice against a man who had promised him freedom, but who had never given it to him. Xerath wanted the power to free himself from being a slave, and was also tearing down a decadent society built on the backs of slaves. Perhaps he believed that he needed to destroy Shurima in order rebuild it up again, and that he would be the one to do it. When he was unexpectedly freed, he may have had regret at the time, but he had already set the gears in motion for Azir and Shurima's destruction. He believed there was no turning back from what he has done, and followed his plan to its completion. In the end, things didn't turn out as planned.
Xerath was designed by David 'Volty' Abecassis with RiotRunaan and Ironstylus providing his original creative concept and art, respectively.
A previous joke (removed during his latest rework) was a reference to the Power Thirst video
His newest joke added as of his latest re-work may be a reference to Genie referring to the lamp ("Phenomenal Cosmic powers: itty bitty living space")
He has an exclusive joke for the Japanese server, referencing Dio Brando/DIO's "MudaMudaMuda (Useless! Useless! Useless!)" cry from the JoJo's Bizarre Adventure series as seen in the official Japanese VO here.
He has an exclusive joke for the Brazilian server, inspired by a Windy of Tenebra (a Tibia player) conversation in TeamSpeak. A comparison can be seen here.
Due to the community's popular demand, both of Xerath's skins were reworked. They both received new particle effects and colors due to them being too similar to the Classic skin before the rework. Battlecast Xerath [S|L] has red particles and Runeborn Xerath [S|L] has green particles.
If Mordekaiser's ultimate, Children of the Grave, is on Xerath when he dies, the neon coloration of the skin will still be on the ghost. Classic skin will be blue, Battlecast will be red, Runeborn will be green, and Scorched Earth will have a lava texture, this is entirely unique for Xerath as all other champions lose all color and become grey and transparent while they are ghosts.
The reason for this is because his body is a visual effect and not an actual model.
It might be a reference to the military doctrine of Scorched Earth, in which anything deemed useful to the enemy is destroyed.
His appearance and armor bears a similarity to Pyroviles, a volcanic alien species featuring in the fourth series of Doctor Who - "The Fires of Pompeii" episode. The Skin's splash art features a volcano in the background that shares a resemblance to Vesuvius.
He shares this theme with Renekton. Perhaps these skins show how Renekton and Xerath were at the locked tomb according to their new lores.
Xerath is allied with Renekton as they spend millennia together trapped in a tomb. He likely drove Renekton mad over the ages, who is now a relentless creature of pure anger.
Xerath Does not see Renekton as a noble hero, he represents power being granted to the few by a corrupt society. In Xerath's eyes, Renekton helped to guard a city of subjugation.
Xerath is also allied with Cassiopeia, as she is the one who set them free from the tomb.
Xerath is a mortal rival of Azir, as the magus tricked and killed the emperor to become an Ascended as revenge for with holding the promise of freedom from being a slave.
Azir has returned ascended himself, and is a potential threat to Xerath.
According to Ryze, Xerath is an "Abomination of a mage" and that his hold over the magical powers he wields is "feeble".
In Xerath's outdated League Judgement it was revealed that he had a friend called Tabia. The two of them seemed to have romantic feelings for each other. Tabia tried to interrupt Xerath's transformation, who envisioned himself living a normal human life and dying as a mortal with her, and truly decided to cancel the ritual. Tabia was however killed by a falling statue, violently leaving Xerath with nothing left to turn to, but his ascension (he did consider just letting the magic kill him, but the ambition won him over). Whether or not Xerath still grieves for her is open for interpretation.
He is being hunted by Kalista for his treachery of Azir.