animate.css/source/rotating_exits/rotateOutDownRight.css

@keyframes rotateOutDownRight {
  0% {
    transform-origin: right bottom;
    transform: rotate(0);
    opacity: 1;
  }

  100% {
    transform-origin: right bottom;
    transform: rotate(-90deg);
    opacity: 0;
  }
}

.rotateOutDownRight {
  animation-name: rotateOutDownRight;
}