New BG is a lot of fun,everything is very powerfull.
Duo is one of the signature cards and after considering it a bit i think it is a very bad card from a design point of vieuw.
The problem with duo is that it is , in many ways , a win more card. Though i guess a more accurate description is that it allows you to seal the deal if you are slightly ahead and find it early.
You cant play duo when you are behind,you will just die. So its a card that can only be played by players who are already ahead.
You cant play it late in the game either unless you are very strong in which case it will just amplify your advantage.
So what duo does is allowing people who find it early and/or who are somewhat ahead of the lobby to run away with the game very early on. It removes any comeback potential for the other players.
And this is why at say 8-11 gold there is an enormour difference in strenght in the lobby. Where you can easily take 25 damage more or less out of nowhere. I have ko-ed people at first place in lobby by doing 30+ damage more then once. You are ahead,greed with duo and take some damage. And then you spike so hard that virtually noone can compete anymore.
So ya. Its a very fun card but i dont think it is a healthy mechanic for the game. It is to polarizing in favor of people who are already ahead and/or who find it very early with a good target.
I dunno,it would be sad to remove the card but i dont see a good way to change it either. 3 turns would be to long and at tier 5 it would be kinda late.
Edit:
Win more cards i dont mean in a bad way by the way.
They are looked down upon by many but that is unjustified. If you are 60% to win the lobby and you find a card that turns it into 95% to win the lobby. Then that obviously is a very good and usefull card for you.
Its a fun card though and a creative design. It also leads to spectacular comps which is pretty awesome. It will be kinda sad if it had to go.
But i dont think the mechanic is healthy in general.
And unfortunatly i dont see how a nerf will change much.
It will be either unplayable or make it so its only playable by people who are even further ahead. And the basic mechanic where it sort of wins the game (small exageration to make the point clear) will remain the same.