If they add trading, it must be far and intelligent trading. Like 6* or a certain number of 5* for 6*, 5* for 5*, 4* for 4* and 3* for 3*. And nothing stupid like anything for anything. 100 2* or 3* don't worth 1 5* or 6* but some games don't even know this...

And what we need is a new buffed Solar Blast system. It's too weak and useless right now. And Solar Blast girls are too useless to.
Against event or story pests, it's useless since they are too weak to survive one turn. On hardest maps, Solar Blast deals not enough damage to be reliable. We need something better.