[Idea] ritual spell

The ritual spell is an EPIC card that would be found in FROZEN PEAK. Its elixir cost would vary, it uses up however much elixir is in your bar when deployed.

The ritual spell is an investment that is made, the more elixir you spend, the longer the duration.

It acts effectively as a "spell spawner" in a sense, it would automatically generate a spell at random times as a quick counter to a troop that is placed.

Allow me to put it into a game scenario, say you deploy the spell behind your tower, you don't want it being targeted of course, you have invested 5 elixir and the lifetime will be 1 minute (20 seconds per elixir) and they deploy three musketeers immediately at the bridge, the card can see this and decide on a spell to use to counter it. It could be as effective as a lightning or as useless as a rage!

I'm open to suggestions as this is my first idea post and am sorry for the somewhat poor formatting as I am in mobile, please give feedback on the card idea as it was something me and a friend came up with.