You evoke a blade of translucent-blue lightning in your free hand. The blade is similar in size and shape to a long sword, and it lasts for the duration. If you let go of the blade, it disappears, but you can evoke the blade again as a bonus action. You can use your action to make a melee spell attack with the blade. On a hit, the target takes 3d8 Lightning + 3d8 Cold damage, their movement speed is lowered by 5ft, and flying creatures lose their ability to fly. This lasts until the target finishes a long rest. The freezing blade sheds dim, monochrome light in a 30-foot radius.