Here's a try for another version. It took some time to find a wording that makes sure only four cards can be used before the effect is gone, and still feels simple (I disliked that you could place tokens on a full pile and piledrive it afterwards without a problem, so with my version the effect wears of even if the cards are gained afterwards). I'll just use "School" as a name, as "Something extra" is a bit confusing.
School
Action - Looter, 2$
+2$
Trash this.
Put a school token on any scholar pile. When a player plays a copy of a scholar piles top card, and that pile has a school token on it, he resolves the top ruins of the ruins pile, first.
Setup: Turn the top 4 cards of all action card piles in the supply 90 degrees clockwise. Piles containing cards that are turned that way are scholar piles.
FAQ: As soon as it contains no more turned cards, a pile loses the "scholar pile" status. Playing a copy of its top card has no special effect, then. When the ruins pile is empty, school tokens have no effect. The ruins pile starts as a scholar pile, itself. The effect of the played card has no effect on the ruins, they are not gained when resolved, nor are they in play or played. It's as if their effect was listed on the played card itself. School tokens may not be removed after the 4th card is taken (not that it matters, as they are not limited). Several tokens do not stack. Ambassador returns cards in the normal position, which only matters after the 4th card was taken, so ambassadoring can't make a pile a scholar pile again. When looking at supply cards, they need to be returned how they were. The "copy of the top card" wording matters for mixed piles as well as for hypothetical cards that can put cards in foreign piles.