[GAMEPLAY]-Poro King Mode & Malzahar Ultimate

I just played a match of Poro King and on the enemy team the Malzahar was able to start his Nether Grasp and lock a player in place then press his "To the King" ability to return to his team's summoned Poro King and it would not drop the animation or damage of his ultimate. He did it to me right at the end of the game and he was half way across the map while I was rooted and taking the full damage of his ultimate. Please fix. Thank you.