The effect is permanent, it will be applied to all attacks originating from that town from now on.
Okay, so you used one "Ares' Rage' item from your inventory on town X. The effect is on the first level, which means all attacks from X will have a +1% attack bonus. If you have any "Ares' Rage'...
I tested this and it's working as intended.
Just to be clear, by using it I mean selecting the item in your inventory/event window and clicking "use" (multiple times to increase level). Is that what you did?
The number of attacks you make from the town where this effect is active does not...
Ares' Rage is a stackable power, meaning that using it multiple times on the same town will increase its level (up to level 10). It cannot be leveled up any other way
I can't seem to be able to reproduce this issue.
Are you getting any errors when trying to send the message?
Can you try disabling scripts and doing a force refresh (ctrl + f5)?
As mentioned in the announcement, this world will be available on mobile apps only after the next update. The next app version will be published next week if everything goes alright.