Tarkir set.

see Sarpadia for Scene card type

­Sarpadia says "Scene is new permanent card type. It is played whenever a land can be played and uses up a land drop. Scenes have no mana cost, and do not generate mana."

That's the first line I read when following that link. So what do the mana symbols do in the top right corner.

I also don't think it's a good idea to introduce two permanent types with different rules but the same name across two sets even if you keep the sets separate, but this seems clearly also not a damageable permanent like Modern Metropolis apparently is.

Really, I check out different versions of this card type across the site and none fits exactly to this card. I think you should create a detail page for this set explaining card types you use in the set a person knowing only the comprehensive rules can learn from - and make sure it fits to the cards you put in the set.

Eh; I the intent was pretty clear: "Scenes are enchant worlds that additionally use your land drop"

Except that using a land drop is not mentioned in the parallel rules write-up of Temur Frontier neither is the world rule - and those have mana costs, but also have a destiny value.

There are two mutually exclusive sets of explantions and each set explains parts of this and neither explains this fully without contradicting the card.

One of the design weaknesses of world enchantments was that they forced themselves to be symmetric. This is an effect you usually wouldn't want to pay to give your opponent access to on an enchantment, but on a scene/world enchantment it suddenly becomes better design?

In my personal rules I have applied the philosophy of the recent change to the legend rule/planeswalker rule (every one gets to have one) to any uniqueness rule (the world rule and any custom type uniqueness rules).