here are some cards that i think would be cool.
first one is incinerator its a shield and costs 9
and has, deal 1 damage to all attacking creatures for each 20
you have, upped is incinerator does the same but costs 7
the other card is ghost, its a 0/0 that costs 6
and has, this cards attack and defence are both random between 0 and 10 your opponent can't see what this cards attack a defense are, upped is elite ghost and costs 5
and has the same effect.
feel free to coment.