The Story of Veigar
Veigar is a yordle who spent years imprisoned in a Noxian work camp, where he was forced to study dark magic for their benefit. This experience produced someone with exceptional power in the dark arts and a personality that has crystallized around the concept of villainy as both identity and aspiration. He wishes to be evil. He practices his evil. He has given himself evil titles. He is, in practice, significantly less evil than he believes himself to be, which is either a tragedy or a comedy depending on your perspective.
The irony is that Veigar's natural state — yordle warmth, desire for belonging, the communal instincts of his magical people — keeps bleeding through the evil facade. He will help someone and then be furious at himself for it. He will be kind and then deliver a monologue about how he is not kind, he is terrifying. The magic he wields is genuinely powerful; his dark energy is not a performance. But the dark mage archetype he is trying to inhabit keeps colliding with what he actually is.
His imprisonment is the serious part of his story — years taken from him, magic extracted from him, identity stripped from him — and the villainous persona may be the most human response to that: if you're going to be feared, become the thing that should be feared. He escaped. He's been getting revenge on Noxus ever since, in ways that are periodically effective and periodically theatrical. He is not harmless. He is also not quite what he wants people to think he is.