You can now bind the multi-attack feature to cards(currently 5cards supported). My tests worked fine. So I am searching now for persons, who like to play with this mod and have the membership to find hidden bugs.
The game is at https://www.warlight.net/MultiPlayer?GameID=13469217
If it has already started, you can invite me to a new game or I will invite you.

Is it called Blitzkrieg-Card? ;)

no just added the multiattack function to the function of the other cards. It is not possible to create new cards yet.