Tomonoshin will be unrestricted, and Obstruct put to 1! Check out the details on the official site.
■ You may only cast this card if you have a «Drametal» on your field. ■ Choose and use one of the following two. You may only cast "Cho-Tokyo Gambit" once per turn. ・Return all monsters on each player's field to hand. ・[Counter] Put the top card of your deck into your gauge, and draw a card for each of your oppressed area.
To lose a piece to improve the situation and formation is a standard move. Pretty well-known too, you didn't know?