Hmm, limited use really, again mostly due to duration. A 10th level cleric could summon the lantern archon for 1 minute and that may be enough time to describe the location in accurate detail, provide a brief message, and deliver this brief message. Of course such a description would need to be "detailed" as many churches of the same diety would have similar aspects. It would help if an individual was waiting in a room and expecting a scheduled message so the Lantern can teleport with greater ease.
Not a bad idea, only useful for contacting mid-low in power churches. Most diety churches that are powerful enough/lots-O-gold are built with permanent wards that prevent teleportation I'd imagine.
If the PC goes through all the trouble to set-up a reliable line of communication this way there is no trouble with this use. Keep in mind though that duration is very short especially at low level and would not likely be able to be useful at all in delivering a message besides a two or three word message.
I wouldn't worry about it much. I'd only let a PC do it if they are at the church when they think of it, so they go through the trouble of memorizing the details. If not, Wisdom check baby to get an accurate enough recall. Say between DC 10-15 depending upon the uniquness/run-of-the-mill church.
if this is possible it seems that every church in the world would be in constant communication with one another.
Well many of the Chuches of the same diety ARE in fact in communique with one another on a regular basis or at least they should be if they are of a coherent organization. If not, then the churches WOULDN'T contact one another because they disagree with policy, etc or do not wish to. Simple as that.
Now again, this use for the Lantern Archon won't be very useful for these churches to communicate due to the duration, only short messages may be sent in this manner. Unfortunately Lantern Archons won't be able to carry back a written message due to the lack of arms/hands, nothing to hold a note with. A Hound Archon on the other hand could do so.
Its a rather creative alternative for emergency communique though and I wouldn't get in a bunch about it mate, seems reasonable enough as long as apply the realistic limits to the spell according to the short duration, accurate description, and no-arms/no-note carrying capacity.
Cheers!
