The hydra next to the mayor in the last fight of zone 5 on heroic does damage to sonny and veradux from 800 to 15000+ ...why? that's luck...I have currently about 9000 life and I must reload each time it hits me for that crazy amounts. I am a biological so I try to have mayor stunned until this little pest dies.. I just mean lucky hits shouldn't get so high damage..
His damage isn't random, he has different attacks. The attack that does low damage restores focus to him, the other deals high damage and costs focus. Since he's completely drained at the beginning of the battle, a good strategy is to defeat it before it gets its focus back.