New spell: Invisible spell

I will like to ask super cell to add invisible spell which creat ring where troops will be invisible inside the spell and defending like cannon inferno tower and eagle artillery etc not work on troops while they were inside spell. There will be 3 level of spell level 1 (7 second) , level 2 (10 second ) and level 3 or max (12 second ). This spell will help the player of townhall level 10 and 11 and they get time to destroy huge destruction defence like inferno tower and eagle artillery. The space of spell will be 3.