The Umbrella Academy is a bizarre show. This makes sense, given the fact that its source material, a Dark Horse Comics publication of the same name, is as nonsensical as it is beautifully illustrated. The Netflix original series has time travel, animal-headed hit people, peculiar superpowers, a suit-wearing monkey who talks, and an alien father figure. Perhaps most surprising, despite the show's quirkiness, it has a lot of heart.
No character is a better representation of the series' carefully toed line between hilarious and earnest than Robert Sheehan's (The Mortal Instruments: City of Bones, Mortal Engines) Klaus Hargreeves. Sheehan's performance has been widely praised by critics and fans alike. Over the course of three seasons, he has provided countless fascinating storylines for the wide viewing audiences that The Umbrella Academy has amassed.
It's fair to say that The Umbrella Academy has become something of a cult classic, and given the fact that Robert Sheehan's Klaus Hargreeves is the only character on the show that has had the sticktoitiveness necessary to become a cult leader, he may be the Hargreeves family member that best embodies the chaotic character of the series.
Here's why Robert Sheehan kills it as Klaus Hargreeves in The Umbrella Academy season three.
Robert Sheehan's Haunting Performance 
Though it's fair to say that the entire cast of The Umbrella Academy is talented in their own right, from the release of season one in 2019, the breakout star of the series was undoubtedly Robert Sheehan. His character, Klaus Hargreeves, has a way of gallivanting around the screen. In some ways, his airy, sarcastic persona is reminiscent of Johnny Depp's performance as Captain Jack Sparrow, as many of the show's viewers have pointed out.
Though he is frequently utilized as the show's comic relief, the story of Klaus Hargreeves isn't all fun and games. He struggles with substance abuse issues, and in season two, when the characters find themselves stranded in the sixties, he is forced to hide his sexuality and later watches his true love die in a Vietnamese jungle. Finding the right balance between humor and heartbreak would be an impossible challenge for most actors, but Robert Sheehan expertly threads that needle. He has had audiences both laughing and crying along with Klaus Hargreeves.
Klaus Gains His Incredible Power
During the first season of The Umbrella Academy, Robert Sheehan's Klaus Hargreeves had almost no supernatural abilities, with the minor exception of being able to communicate with his late brother, Justin H. Min's (Faking It, Pure Genius) Ben Hargreeves, in large part due to his rampant substance abuse issues. However, as Klaus worked to resolve his childhood trauma, his skillset began to expand.
However, none of the abilities Klaus Hargreeves showcased in previous seasons of The Umbrella Academy could have prepared audiences for the new power he gained in season three: immortality. It is revealed that Klaus has been incapable of dying for his entire life, though the exact time frame of his resurrection was seemingly random. With help from an unlikely source, Klaus' adoptive father, Sir Reginald Hargreeves, he is able to perfect that power in season three, forever cementing Klaus Hargreeves among the most powerful members of the Umbrella Academy.
Teaming Up With Sir Reginald Hargreeves
Every member of the titular Umbrella Academy had issues with their adoptive father, Colm Feore's (The Chronicles of Riddick, House of Cards) Sir Reginald Hargreeves. Sir Reginald kept Elliot Page's Viktor Hargreeves sedated throughout their childhood. He transformed Tom Hopper's Luther Hargreeves into a human-ape hybrid and later sent him to live alone on the moon under false pretenses.
However, it's possible that Robert Sheehan's Klaus Hargreeves had the worse relationship in the entire Umbrella Academy with his adoptive father, who berated his son for his inability to fully harness his powers, and (as it is revealed in season three) left him to die in a mausoleum in order to prove his regenerative abilities. This made it all the more surprising when he paired up with the alternate reality's Sir Reginald Hargreeves in the latter half of The Umbrella Academy season three. This team-up represented a new emotional layer for the character, and Robert Sheehan expertly showcased his character's repressed inner child.
With his newly discovered sense of self and the freshly unearthed sense of purpose, it is exciting to think of all the ways in which Robert Sheehan's Klaus Hargreeves can be utilized in future seasons of The Umbrella Academy. Frankly, the show just wouldn't be the same without the quirky Klaus, whose free-spirited antics are the ultimate embodiment of the Netflix Original series' chaotic energy. Given the character's new and expanded skillset, in combination with Robert Sheehan's incredible acting ability, Klaus Hargreeves will continue to kill it regardless of potential season four storylines.