Spell towers

It would be nice if clash of clans added spell towers. They would have to be reloaded every time they are used, and they would have an effect radius.

1. Well there is already a hidden Tesla, which is like lightning
2. Rage tower: boosts all defenses nearby
3. Healing tower: heals all defenses nearby by a certain # of hp
4. Freeze tower: freezes all enemy troops in the area for a limited time

Also, it would be cool if when you upgraded a wall a certain # of times, it could damage enemy troops if they stood too close.