Vel'Koz
It is unclear if Vel'Koz was the first Void-spawn to emerge on Runeterra, but there has certainly never been another to match his level of cruel, calculating sentience.
Balance trajectory
Balance trajectory tracking is coming with the LoL patch parser. For now, check the official patch notes for the latest changes affecting Vel'Koz.
Same class
Mage
Ahri
Innately connected to the magic of the spirit realm, Ahri is a fox-like vastaya who can manipulate her prey's emotions and consume their essence—receiving flashes of their memory and insight from each soul she consumes.
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Anivia
Anivia is a benevolent winged spirit who endures endless cycles of life, death, and rebirth to protect the Freljord.
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Annie
Dangerous, yet disarmingly precocious, Annie is a child mage with immense pyromantic power.