Possible mechanism to cast arts etc. on a *room*

[Noidea]

An idea I've had for some time, either for this game, or failing that, for Underlight 2.

Our RPs often involve casting arts or what-not on a room itself, or some part of it. For instance (taking SoT examples), the repairing of Trinity Sanctuary involving "poisoning" the room to break its power, the turbulent creation of the new gens, or EC casting arts on their plants.

Could this be made part of the game system, by treating a room as a creature? The way it would work would be, you'd have an invisible creature (or only visible as a dot, so people could aim at it) fixed in the middle of a room, which would spawn as soon as you entered the room, like a normal mare (but, obviously, not attack). That way, people could evoke arts on the environment (in the form of this marker-creature) just like they do on other characters.

It would need to be possible for the GMs to put conditions on the "creature" of a particular room, e.g. poison, so people could try to Antidote it - or code that would be tagged as poison, for Antidoting purposes, but damage nearby *dreamers*. They'd reset when it respawned, I suppose, which is probably as it should be since permanently affecting a room is traditionally a major job, but clearing them would have its effect at the time - and the GMs could change them manually to reflect a successful big RP.

One obvious example of a use for this would be banishing mares from a room - instead of just miming with emotes, you could cast your arts and have the full light-show.

This seems reasonable to me, but I don't know how much of it actually corresponds to how the current engine works.

What do other people think?