you can attack some1 by clicking "attack user" under avatar.. and depending on your strength and who you attack your strength n stats will go up or down.. the atkshop is where you spend you "gil" to gain health if you've lost it or want more.. or got killed..
the guilds.. when people have enough gil they can set up their own guild.. which is like a team.. people can join that guild.. when you have multiple guilds you'll have teams attacking each other..and donating gil to team members etc..
its a fun little forum attack game