Let’s draft together the pattern of this asymmetrical blouse.
Start from a basic block without darts.
Mirror back and front for the asymmetrical style, on both raise the shoulder tip by 1cm, lower the armpit by 3-5cm and move outwards by the same amount to draw the short dolman sleeve.
Shape the side seam as a non fitted silhouette.
Work the same way on back and front: draw the new neckline from one side of the original one to the shoulder tip of the other side.
Then draw 4 slash lines: two from the shoulder to the side seam under the armpit (3-4cm apart), one from the armpit of the other side to the opposite side seam above the waist, the last one across the waist.
Cut through all the lines.
Separate by 4-5cm the pieces at the two lower slash lines, separate on the armpit edge by the same amount the top two keeping the pieces together at the shoulder line.
Redraw both blocks as two separate pieces.
To make sewing easier and the blouse fit at its best, the slope of the lines should be the same.