On multiple occasions one of my characters will attack an opponent's character and see their health drop only to see it then regain back. There have also been many times where I have killed the enemy's character and they perform the death animation, but then come back to life and start attacking and kill my character. The opponent doesn't use any healing buffs so it just comes off as boggling and unfair. It happens with almost every opponent so unless everyone in the game is hacking, this is one major bug in the game.