New spell invisibility spell

I would like to add a new spell called invisibility spell it is a dark spell which keeps troops inside it hidden
Level 1- 4 seconds of invisibility
Level 2- 6 seconds of invisibility
Level 3(max level)- 9 seconds of invisibility

The cost of lvl 1 invisibility spell is 125 dark elixir of lvl 2 spell is 150 dark elixir
Lvl 3 - 200 dark elixir
To upgrage spell to lvl 2-25000 dark elixir
To upgrade spell to lvl 3-50000 dark elixir


This spell will be unlocked at lvl 5 dark spell factory after unlocking skeleton spell and upgrading dark spell factory and be upgraded in max lvl laboratory

Please read the sticky thread before posting.

Invisibility/fog/smock or spell ideas that make troops untargetable are all ruled out.