Dark elixir

I'm upgrading my town hall to lvl7 and in past raids I have collected dark elixir and it will not get stored or given to you when u get th lvl7 so I think it could be saved in a special behind the scenes thing and then when they get th 7 then they can get the dark elixir also it can't be raided or stolen if you don't have th7

It's not hard to raid DE at TH7. You could easily make back the 5k or so DE that you couldn't take as a TH6 in a day.