This is a trap, like a bomb or spring trap, that can be unlocked at Town Hall 7 called the Spell Corrupter. Essentially, it weakens spells' effects, and at higher levels, the trap would cause spells to do the opposite of what it normally does.
How it works: When a player drops a spell within a certain radius, let's just say 5 blocks, a beam of light like the healer's will pop up out of a hatch in the ground like a seeking air mine and quickly hit the spell as it falls to the ground. The spell will then be modified, the details of which are explained below.
Details/Upgrades: This trap is unlocked at Town Hall 7. It can be rearmed like any other trap, and can be used 1 time after it has been rearmed. At Town Hall 7, you can only purchase a single level 1 trap. At Town Hall 8, you can upgrade the trap to level 3. At Town Hall 9, you can upgrade the trap to level 5. Finally, at town Hall 10, you can purchase a second trap and upgrade both of them to level 7.
Effects: At level 1, the affected spell's potency would decrease by 25%. At level 2, this percentage increases to 50%. Then to 75% at level 3. At level 4, the spell would completely nullify the affected spell. At level 5, the affected spell would perform the reverse action at 25% potency. This would increase to 50% at level 6, and to 75% at level 7. An example for this could be as follows:
Example: The spell I am using for the example is a Level 4 Lightning Spell.
*No trap - 390 damage (deals damage to buildings or clan castle troops with each strike)
*Level 1 trap - 293 damage
*Level 2 trap - 195 damage
*Level 3 trap - 98 damage
*Level 4 trap - 0 damage
*Level 5 trap - 98 healing (heals buildings or clan castle troops with each strike)
*Level 6 trap - 195 healing
*Level 7 trap - 293 healing
Of course, these statistics could be raised or lowered to best fit the game, but it's a good start in my opinion.
Price: Prices are as follow:
*Original purchase (Level 1) - 500,000 gold
*Level 2 upgrade - 750,000 gold
*Level 3 upgrade - 1,000,000 gold
*Level 4 upgrade - 1,250,000 gold
*Level 5 upgrade - 1,500,000 gold
*Level 6 upgrade - 1,750,000 gold
*Level 7 upgrade - 2,000,000 gold
Now keep in mind that these prices are based off of the fact that this trap can only be used 1 time before it needs to be rearmed, unlike the Hidden Tesla. Also, each trap can only affect 1 spell and has a rather small range. These three things combined causes the price to drop to what it is. The price also goes up very consistently, like the affect it has on spells.
Let me know what you think! I am always open to constructive criticism. Praise would be nice too.
Edits:
1) I have a new idea to balance the power of the trap. Instead of basing the potency reduction off of percentage points, maybe the spell could reduce the effect by 1 level. In my example above, instead of the level 1 trap reducing the damage to 293 damage, maybe it reduces damage to whatever the level 3 spell has. Of course, on the opposite end, the spell effect can only be reduced to the level below as well. For example. If the level 7 trap corrupted a level 3 lightning spell, it would heal the buildings by whatever a level 2 lightning spell is supposed to damage. Of course, this is just an idea, and if it doesn't make much sense, just let me know and I'll try to clear it up better.




