Question Card Game UI Design

Hello there,

I'm creating a new cardgame, and I stuck at some point, and would be really glad, if anyone could give me a direction or little help to go on.

Currently I'm working on the design (most of the mechanics are in place and working). I would like to add some kind of arrow, or line, or indicator when the player plays a card. I'm thinking about like the one in Gwent. If the player grabs the card and drag it, I would like to create a ,,phantom" card at the mouse's location, drag around, and create the line between the original and the phantom card.

Problem is, I'll be honest. I don't have a single clue, how to solve this on UI or where to start. I've already created the phantom card, it follows and works fine, can be dropped, when dropped the real card moves there with a little animation, but I don't know how to create the line animation as I've never done it before.

As I don't know the effect's proper name either I did not really find help.

If someone can give me a direction where to look, or a link to an existing turorial, or just a theory which I can start on, I would be really grateful.

Thanks for your time.