Have an Idea for some new heroes, that have a set bonus. (The more you have on the team the better bonus) The bonus can have impact on the special skill or maybe the stats.
1: normal skill
2: litlle more damage
3: lasting 1 or 2 extra turn/turné
4: aply dot on nearby enemies (if its a single target dot)
Some might be more creativ then me
And it could be made so that we can stack colors to and still get the bonus if there come more then just 1 hero of each color, so it dosnt have to be rainbow team to det the bonus a player want for the heroes. Then could be made so they are train able and be hotm.