In the 'Reimagining Pantheon' video released on the LoL YouTube channel two weeks ago, there is a focus on keeping the 'character' of Pantheon despite the rework, while making his poke reliable and abilities familiar to old and new Pantheon players.
There is a new focus on a ground fight, to fit with the strong warrior aspect of the Champion, over magical abilities he had previously.
Every ability and spell has been changed for new Pantheon and eager players have been able to experiment with him in the PBE in advance. One notable example of such change is his Ultimate. Grand Starfall is the new name of his Ultimate, replacing Grand Skyfall. The rework has been designed to reward skilled Pantheon players and allow the Ult to have more impact with well-placed and well-timed delivery.
His overhauled kit now contains, in Q, W, E order, Comet Spear, Shield Vault and Aegis Assault, alongside his updated Ult and his passive Mortal Will.
His lore and visuals have also been reworked, with the previous model showing its age as the 28th champion in the game. Pantheon was formerly a man named Atreus. Having reached the peak of Mount Targon but being judged unworthy by the Pantheon, Atreus was taken over by the Pantheon for its own needs, to fight Darkin. Aatrox managed to kill the Pantheon, leaving War to be reborn into a mortal Atreus, miraculously surviving his first encounter with Aatrox and besting the Darkin on his second.
The updated Pantheon, alongside various other Champion changes found in the Patch Notes, are now live on all League of Legends servers. Azir, Jax and Riven have seem cooldown adjustments, while Corki, Shen and Sivir have seen attack damage nerfs and buffs.