Exactly how it sounds, a spell to help keep your troops going in the right direction.

Cost: 30,000 elixir
Time: 45 minutes
Spell Duration: 10 seconds
Spell coverage: 10 tiles
Upgrade cost: 3,000,000 elixir
Spell levels: 2
Spell level 2 improves duration to 15 seconds.

This spell would work to help direct the flow of your attackers, when used all troops in the radius would begin attacking towards the center of the spell. No bonuses added, just help keep your troops going where you want them to.

I am not sure on appearance, maybe just a white shading to show the radius.