Also not to mention Billy's sister is known as the key of untold power much like Dawm is.
Edit:
First off I have to agree with the people who said these are unfair things to compare because they came from someone else. As far as Mutant enemy copying this episode i highly doubt they need to because i do rember it was set as an earlier episode in the series anyway around the same time so neither had enough time to copy oneanother. Much like the vision thing wih Doyle, Cordy and Pheobe because that idea isnt original as well. Many shows have done "That Vision Thing" (NO PUN INTENDED) in a show before. I do agreee though Normal Again was more thought provoking which is why i liked it. I saw the Smallville episode like that as well and i think Smallville's rendetion should be in competition with Charmed and if that were the case Smallville would win because Smallville was more beliavable as far as what they brought to the table in terms of manipulation. Brain Drain was very linear and you knew the outcome of it and you knew the circumstances of the situation completely . In Smallville and BTVS you knew as well but it made you wonder is there really more out there than what we see.
Edit:
Is this the one?
10 Days of Top 10s: Day Five - Best Episodes - Buffy-Boards
Actually the original claim is usually Buffy stole Normal Again from Brain Drain, because Brain Drain appeared first, but when you look at the facts it might not be so clear.
Personally I think what's more likely in that case is the origins of that particular story line are old, and you're bound to see a number of evolutions.
Another thing I'd suggest though is Normal Again is the more thoughtful, and interesting of the two. It attracts more serious study from educated viewers.
First off I have to agree with the people who said these are unfair things to compare because they came from someone else. As far as Mutant enemy copying this episode i highly doubt they need to because i do rember it was set as an earlier episode in the series anyway around the same time so neither had enough time to copy oneanother. Much like the vision thing wih Doyle, Cordy and Pheobe because that idea isnt original as well. Many shows have done "That Vision Thing" (NO PUN INTENDED) in a show before. I do agreee though Normal Again was more thought provoking which is why i liked it. I saw the Smallville episode like that as well and i think Smallville's rendetion should be in competition with Charmed and if that were the case Smallville would win because Smallville was more beliavable as far as what they brought to the table in terms of manipulation. Brain Drain was very linear and you knew the outcome of it and you knew the circumstances of the situation completely . In Smallville and BTVS you knew as well but it made you wonder is there really more out there than what we see.