Show Ghouls - S7-E15
Plot hole: When Leo tells Piper that he believes he found the demon Sargon in the Book of Shadows (which may be the demon Count Roget made a faustian deal with), Piper looks at it and says that they vanquished this demon five years ago. Which would've meant they vanquished the demon with Prue. When in fact the only demon that happened with was Zahn in season 6 episode 6, "Soul Survivor," and they did that with Paige.
Plot hole: When Piper goes back in time to save her sisters from dying and get rid of the Hollow, right after Leo describes it as "time catching up with itself" and the new reality Piper takes over her body. Yet in Season 5 Episode 7 "A Witch in Time", Piper goes back to keep Phoebe from saving her boyfriend but once Piper changes the past, the original Piper fades away and the new reality Piper stays.
Plot hole: When the Avatars agree to rewind time they say that they can either put the world right or save Brody but not both. This doesn't make sense since they're rewinding to right when they put everyone to sleep, which is before Brody was killed.
Valhalley of the Dolls (1) - S6-E1
Plot hole: Phoebe becomes an empath. But in Primrose Empath (S3:E6) Leo tells the sisters an empath is a mortal who has died and come back as an empath, so it wouldn't be a progression of a witch's powers like it is in this episode. Plus Phoebe isn't dead.
Suggested correction: There is a difference between an Empath and the power of Empathy. A true Empath is a mortal that has died and been reincarnated and they are a separate race of magical beings. But other beings, such as witches, can have the power of empathy. It does get confusing because they refer to a witch with empathy as an empath, but that doesn't mean they are true empaths. In addition, Phoebe developed her empathy powers in her 20's as one of her first powers and her power of empathy is the strongest of any being.
And where is this stated anywhere in the 8 seasons of the show?
Plot hole: Paige is able to use the enchantress' powers, but in "Pardon My Past", Phoebe can't use her past life's fire throwing power and Leo tells her it's because her past life misused it so she lost it. The enchantress misused her powers so Paige should not be able to use them.
Plot hole: The demon is killed when Leo proposes, hence before the wedding. So how is he able to break the cake topper?
Witch Wars - S6-E21
Plot hole: In the beginning of the episode the opening screen row Witch Wars has images of the witch Paige saved before the event actually occurred.
Plot hole: It is stated Leo is born on May 6th, 1924. Yet he was in his 20's as Piper's ex-lover in his past life around 1924. It also stated that that is when he died and became a whitelighter but the war wasn't until 1942. He died shortly after that meaning he didn't become a whitelighter until after 1942.
Plot hole: In the final episode Piper cast the spell with her mother Patty and grandmother Penny to get the Hollow out of (past) Piper, Phoebe, Paige, Billy and Christy. It worked. But in episode 4x13 Charmed and Dangerous, the only way to contain the Hollow is by good and evil working together... which wasn't the case in the final episode.