A New Champion Approaches: Xerath, the Magus Ascendant

Lore:

In the ancient civilization of Shurima, the mage called Xerath practiced magic with undying passion. He believed that with enough magical power, he could gaze into the heart of Runeterra to know the secrets of history and the universe beyond. Such magic was beyond the limitations of a mortal body, but Xerath obsessively pursued a path to infinite power nonetheless. With every breakthrough he grew more and more powerful, yet not without consequence. Xerath's increasing arcane abilities wrought havoc on his physical form. Desperate, he undertook a dangerous ritual to transcend his dying body. The outcome would be immortality or self-destruction. Violent magic unleashed during the ritual caused devastation throughout Shurima, but when the dust settled, Xerath emerged as an ascended being of pure arcane energy.

Free of flesh and bone, Xerath held nearly infinite power at his command. However, in the wake of his chaotic ritual, the mages of Shurima feared his careless disregard for life would bring ruin to the kingdom. After a terrible struggle they subdued Xerath, but they could not destroy his ascended form. Instead they trapped him within an enchanted sarcophagus and sealed him in an underground tomb. Eons passed, civilizations rose and fell, and Xerath's imprisonment was lost to memory. For centuries, Xerath's vast power tore away at the sarcophagus and weakened its spell. Finally, he willed forth a burst of magic that shattered his prison, but its core remained, containing Xerath and his power within its broken pieces. Seeking to rid himself of this burden, he was drawn to the magic of Valoran's nexuses and found he could absorb their power. Yet the nexuses had gatekeepers: petty mages known as summoners. Xerath knew his key to true freedom from his prison lay in gaining their trust, and he offered his power to the League of Legends. 

“I have no need for vengeance. Time has brought ruin to the mages of Shurima and I alone remain.” – Xerath, the Magus Ascendant

Abilities: 

Ascended Form (Passive): Xerath feeds on arcane power, making him increasingly resilient to physical harm. He converts a percentage of his Ability Power into Armor.

Arcanopulse: Fires a long-range beam of energy, dealing magic damage to all targets hit.

Locus of Power: Xerath anchors himself to source of magical power, increasing the range of all spells and granting him bonus % Magic Penetration. Although he is immobilized while Locus of Power is active, his movement speed increases upon disabling the ability.

Mage Chains: Deals magic damage to an enemy and marks them with Unstable Magic. The next spell Xerath strikes this enemy with stuns them.

Arcane Barrage: Calls down a blast of arcane energy, dealing magic damage to all enemies in an area. May be cast up to three times before going on cooldown.