The MCU finally explained exactly why Agatha Harkness is a witch-killer in Agatha All Along.

Agatha All Along, Kathryn Hahn

The Agatha All Along finale laid out the reasoning behind why Agatha Harkness kills other witches in the MCU.

Following Agatha All Along‘s official introduction of the MCU’s Death, the series left plenty of questions to answer in its final two episodes. With half of Agatha’s coven having met their end, the stakes rose for Kathryn Hahn’s fan-favorite character.

While most of the last two episodes wrapped up the present-day story, fans got a much-needed look back at Agatha’s origins from long before she first set foot in Westview.

Why Does Agatha Kill Witches in the MCU?

Warning – the rest of this article contains spoilers from Episodes 8 and 9 of Agatha All Along.

Episode 9 of Marvel Studios’ Agatha All Along largely centered on flashback scenes showing Agatha Harkness’ true origin story in the MCU.

In 1750, Agatha gave birth to her son, Nicholas Scratch, who had been teased since Episode 2 of Agatha All Along. However, Aubrey Plaza’s Lady Death was there as she was giving birth, indicating Nicholas was not supposed to live at all.
Agatha Harkness and coven in Agatha All Along

Marvel Studios
As shown in WandaVision Episode 8, Agatha knew about her ability to take other witches’ magic when hit with it, which, in turn, killed them. However, she continued to do this not only to grow more powerful but also to keep Death at bay so she could have more time with her son.

This is shown to be part of the deal she makes with Death as Aubrey Plaza’s character reluctantly allows Nicholas Scratch to live in exchange for other bodies.
Agatha Harkness stealing magic in Agatha All AlongMarvel Studios
It is also revealed that Agatha and Nicholas made up the fabled “Witches’ Road” song, which Agatha used to lure other witches to her. Hahn’s villain would then seduce other witches into forming a coven with the promise of finding The Road, goading them into blasting her with their magic so she could steal their power.

The only time Agatha did not pull this ruse was the moment when Death catches up to her and her son, taking Nicholas Scratch with her and ending his life.
Agatha Harkness stealing magic in Agatha All AlongMarvel Studios
Agatha continued this ruse for centuries, and she was even planning it again in Agatha All Along Episode 2 as she assembled Alice Wu-Gulliver, Lilia Calderu, Jennifer Kale, and Sharon Davis. To her shock, The Road actually appeared only momentarily after urging them to blast her thanks to Billy Maximoff’s powers.

What Happens to Agatha in Agatha All Along?

Surprisingly, Agatha does not manage to make it out of her own solo series alive after surviving for centuries off the life force of other witches. Sealing her fate with a kiss of death, Agatha sacrifices her own life in Episode 8 to save Billy Maximoff, who is also living on borrowed time in William Kaplan’s body.

While Wanda Maximoff was once again confirmed to be dead in the MCU, her son Billy finally evolved into his full Wiccan persona with a comic-accurate costume. He also got a similar send-off from the Westview residents, enduring a walk of shame similar to Wanda’s in WandaVision.

Moving forward, the next step in the road for Agatha and Billy seems to be finding Tommy Maximoff, who found his own vessel in Episode 8 the way Billy did with William Kaplan. Agatha will also have to do this in ghost form, and it appears as though she and Billy will continue to work together, possibly reluctantly.

This sets up the early stages of Marvel Studios’ potential adaptation of the Children’s Crusade comic (a story that young Billy Maximoff star Julian Hilliard wants to see adapted in the MCU).

That comic follows Billy’s search for the Scarlet Witch, who is thought to be dead, although she could be switched out for Tommy. However this plays out, Agatha and Billy’s time in the MCU looks far from done.

All nine episodes of Agatha All Along are now streaming on Disney+.