Corrected entry: Why does Chris have his powers when he went to the past if the Charmed Ones never had their powers when they went to the past, for example in "That 70's Episode" or "Witchstock?" If Chris came from the future and traveled to the past, shouldn't he have lost his powers too?
Correction: Maybe in the future they have come up with a spell that allows them to go back in time without losing their powers? It isn't impossible to believe they have improved upon their spells.
Corrected entry: Why doesn't Chris ever use his powers against demons? We know he can use them in this time, since he blows up Leo in "Oh My Goddess" and kills a Valkyrie in "Valhalley of the Dolls", and after "Chris-Crossed", when it was discovered he was half-witch he had no reason to hide them from the sisters, yet he never once used them against a demon, even when one of the Charmed ones is in mortal danger.
Correction: Actually Chris couldn't use his powers up until the "Chris-Crossed" episode because before this episode the sisters couldn't find out that he was part witch because then his cover as just their whitelighter would have been blown. Basically he had to keep his powers a secret until the "Chris-Crossed" episode.
Correction: Bianca states in Chris-Crossed, that with the particular spell that they were using to send him back, his powers would not be affected.