When you find yourself trying to remember a show (or any works) that's on the tip of your tongue but just out of reach, come here - the collective brain of the TVTropes community can probably help. Post all the details you can remember (examples help). If you're looking for a trope, head over to Trope Finder. Have general questions about tropes? Visit Ask The Tropers!
Miar
Since: Dec, 2010
blueharp
Since: Dec, 1969

I vaguely recall an anime that used to air on either Fox Kids or WB back in 2002 or 2003. It was about some crazy professor who traveled time and/or dimensions with his two kids/students/whatever. Somehow, fallen angels were involved.
Ring a bell for anyone?