MArcomage

Shouldn't it be Mass Enfeeble, with a separate weaker Enfeeble card?

Well, technically you're enfeebling your opponent. But the argument could be made you're enfeebling each card...

I didn't imagine any effects targeted the incorporeal force known as the player, nor do I know why making that force weaker would correspond to all of the force's opportunities.

You don't figure that each tower is inhabited by an owner at war with the other?

Not really, there might be a ruler there, but I don't think it's the player. The player's abilities are too vast, and they have too much information. I would say the player is some disembodied, omniscient force that talks into people's heads, and Tower represents the groups of people that can hear the player or are under the player's direct control.

... Too much.

According to old Arcomage, you play as the Acromage which is a title of a person and resides in the tower. So when the tower is destroyed, you perish too.