hypnotize spell

We all know the feeling of forgetting to check the clan castle and losing a battle. So why not hypnotize the clan castle troops?
The spell hypnotizes enemy clan castle units and they will fight with your army. the downside, they will be shot at by the defenses, but there will be a 10 second immunity on the troops that you hypnotize at level 1. so basically, you hypnotize the troops, the troops start attacking the base, while the defenses shoot them but not being able to damage them as they have immunity. Then after a period of time, their immunity will wear off and defenses will be able to kill them. Upgrading the spell increases the time that they are immune. There is no limit of how many clan castle troops you can hypnotize.
Radius: same as poison radius.
Color: bright green.
brewing time: 3 minutes
spell capacity: 1

Level 1, unlocked at th 8, in the same upgrade as eq spell.
immunity time: 10 seconds
cost: 100 dark elixir.

Level 2, unlocked at th 8
immunity time: 12 seconds
cost: 120 dark elixir.

level 3, unlocked at th 9
immunity time: 14 seconds
cost: 140 dark elixir.

level 4, unlocked at th 10
immunity time: 17 seconds
cost: 170 dark elixir.

level 5, unlocked at th 11
immunity time: 20 seconds
cost 200 dark elixir

the upgrade times, costs and laboratory level is the same as the poison spell.
go to http://clashofclans.wikia.com/wiki/Poison_Spell
for details of the upgrade of the hypnotize spell

please comment on your thoughts and how to improve on this spell.

This is a good idea. You may want to consider including your enemy's hero's in this also. Anything in the hypnotize circle will turn on their fellow villagers for a short period of time.