Circle Sewn With Fate / Unlock Thy Hidden Gate - S1-E2
Plot hole: Spoiler - considering what emerges at the ending of the series, Agatha's behaviour in this episode hardly makes sense. She had no trust in the Witches' road; in fact, she knew it did not exist at all, and her only aim was to steal the powers of the other four witches during a fake ritual. However, one of them is a normal human with no powers, one is a witch with her powers sealed and thus impossible to steal, and she literally tells the third one how her very specific energy-stealing power works - which, of course, is entirely absurd considering she had no purpose for her, given the lack of a real ritual.
Suggested correction: She made do with what she could find. Two of the witches had powers she could steal. Since she was totally powerless at that time, it would be enough for her. After taking the power of just one or two, she could have killed the others just as easily. It didn't matter to her that one of them was not a witch at all; she needed four to make them believe they were walking the witches' road.
"I can't steal your magic unless you blast me with it. So if you show a little self-restraint, which, let's be honest, you're gonna need to, all that power is yours to keep." This is not me paraphrasing her for humour or to be concise; it's the actual dialogue to the person she plans to rob of their power. And it is 100% accurate; there is no "spark" she can steal without being hit directly. This level of candour makes sense only if there is an actual point to the ritual, and her subsequent attempt at taunting them is desperation because the ritual does not work, so then, at that point, she has to make do with what she has. Not if the whole thing was a sham to begin with.
I agree it's strange she would warn her about her ability if she planned to have them attack her, but Alice did in fact use her powers on her later without thinking about those consequences. So maybe Agatha hoped she would forget or not show restraint once she angered them enough. The witches in the past all seemed very eager to attack her after being taunted, and seemed to have been working for her for centuries too, so why not now?