It's this time in the anime season, and many of the shortest titles have already wrapped up. The World's Finest Assassin is no exception. Based on a light novel of the same name, and produced by Silver Link, a studio that's famous for its isekai, The World's Finest Assassin wasn't groundbreaking but many found it fun to watch. Below, we explain everything you need to know about the ending of the 12-episode show. Beware of spoilers:
The World's Finest Assassin Ending Explained: What Happened to Dia?

A few episodes ago, Lugh had been faced with a devastating task: assassinate Dia, whom he loves dearly. As we found it later, his plan had been to fake her death instead, hoping that this would be enough to satisfy. He would then sneak her into the Tuatha De family region.
The arrival of Setanta MacNess thwarted Lugh's plan. Knowing he wouldn't survive a direct confrontation with the hardened warrior, Lugh had to make a few alternations in his plan.
Tungsten turns out to be Lugh's friend. Through a magnetically propelled projectile made of Tungsten, the assassin manages to incapacitate Sentana long enough. We're told that this makes the goddess happy, which is perplexing, as Sentana isn't even the Hero that Lugh must eventually assassinate.
In any case, Lugh succeeds in the most important part of his task; to escort Dia to safety. His family adopts her and she will now pose as Lugh's younger sister. But how will Lugh adapt to that? Will he try to forget his romantic feelings for Dia, or will they resume their relationship in secret?
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The World's Finest Assassin Ending Explained: What About the Hero?

The first season of The World's Finest Assassin confirms that Sentana isn't the Hero. Instead, the person Lugh must defeat is a Lord by the name of Epona Rhiannon. But if Sentana is so powerful, how much more so must Epona be? Undoubtedly, he will present a challenge for Lugh, but we'll have to wait for a potential Season 2 to find out more about him.