"As soon as the nails hit the soil, deep indigo lines blazed between them, forming a triangular seal." Riot has not given Locke a biography in the usual sense. His Universe entry is a short story set over one evening in a town called Brookhollow, and that sentence is its one piece of hard craft: three iron nails, a triangle, and a demon held inside it. Everything we know about the newest exorcist in the world of Runeterra comes from what he does in that scene and what he says to the two people in it.
Who they are
Locke sits at a crowded inn table and orders a drink he has no intention of touching. Across the room a farmer in undyed wool is flirting with a red-haired woman who has a fine lute beside her, comparing her curls to his wife's. Locke turns iron nails between his fingers under his cloak. When the couple leaves he gives his full mug to the stranger beside him, pays, and follows. His lenses let him see in the dark, and he watches the farmer pull the woman into a stand of trees between two buildings. He mutters an incantation, vanishes in ash, and appears in front of them with a stake raised, just as the woman's claws go for the farmer's chest.
The woman is Evelynn. She calls him Corvin, so Locke has a first name and a past with her. He throws the nails, the seal takes her, and she bargains: the farmer is a pathetic old man, nobody will miss him, she has not had a decent meal in so long. Locke reminds her that Brookhollow was off-limits. She says a huntress drove her here, and when he asks what the huntress looked like she changes her face into Shauna Vayne's and points him at the Wyldwoods. He kicks a nail over and the seal breaks. The terms are in the text: tell me where she went, stay clear of this town, and I will leave you alone, "Same as always."
Then the farmer, curled at the base of a tree. A gold chain at his neck carries a locket with an initial, V, and a portrait of the woman Evelynn had been wearing: his wife Victoria, dead a year ago that day. Locke gives him a vial that will numb him long enough to get home, tells him to lock the doors, let the grief out, and let her go, "Or another demon will find you, sooner than later." Then he is gone, out onto the streets of Brookhollow.
Where they belong
Riot's faction pages put Locke in Demacia. The story itself never names a kingdom; it names an inn, the town of Brookhollow and the nearby Wyldwoods. No race is listed; he is a man with tools.
Three champions are linked to him. Evelynn is the other lead of the story: his prey, his informant, and someone he has plainly dealt with before. Vayne appears twice without appearing, as the huntress on Evelynn's trail and as the face Evelynn borrows to describe her; Locke's reaction when he hears the word "huntress" suggests he knows exactly who is meant. Morgana is not mentioned.
In the Riot MMO, as a guess
This is speculation. Locke joined League in June 2026, and Riot introduced him with a scene rather than a chronicle, which tells you what he is for: he is the man who turns up in a small town, sees what the locals cannot, and leaves them with a vial and instructions. That is a quest-giver by design, and a demon-hunting chain through the villages of Demacia writes itself around him, with Evelynn as the thing that keeps getting away. He is not a boss and not a memorial; he is alive and working. The general argument about what champions become to a player is in will champions be playable?, and Locke is the strongest case in this batch for the answer that he is the person who gives you the job.
What we do not know
Whether the game's era, the open question in when is the Riot MMO set?, finds him alive, since Riot has dated nothing in his story and we do not know when Brookhollow's evening falls.
How long "Same as always" has been going on, and what Corvin Locke was before the nails. The story gives him a first name, a set of tools and a rule about one town, and nothing else.