Will the whole deck consist of cards offered by the community? then it is better to set a general theme, like a deck of darkness depending on luck.
@jhoijhoi hehe that's my placeholder author name on the screendesign. @el jerbo most of the cards will be coming from the community. I've already have a few ideas myself that I'd like to add. But the theme holding the cards together will be mostly just them being 'light' :-)
How about Immolation like attack type (basicly the tower can be also a flame). Prety much my idea is when you build the tower it summons fire on the tiles in 1 range and they are permanently there and do a burn/poison dmg per sec to the targets which pass. You can spicy up the tower if you make the 2nd skill buff/debuff to certain types of towers. When there is tower next to this new common it starts to burn it. It will give attack speed buff to darkness towers, damage buff to metropolis and dmg + attack speed DEBUFF for nature.