Since I have a lot of time to kill at work on my new schedule, I recently got back in to Duels. It is a good bit more advanced now, they have added achievements, action sets (these are "cards" you use during a battle to add a strategic layer) and a ton more quests to help in levelling up as well as gaining tokens. If anyone is interested I was thinking of starting a guild. If there are folks interested in trying it out and starting up a guild, let me know.
Here is my referral link, don't know what exactly it gives me to be honest aside from an achievement:http://www.duels.com/users/register/annaliese_morgan
or you can just go straight to:www.duels.com