Zalmarath the bugged and cheater

Can you stop making the game artificially difficult by bugs and IA cheating (aka Blackjaw, Sekemas in cruel mode)
For Zamarath, i can only use basic straight attack with my ranger, freezing salvo, dont touch him as poison growth.
I spam the same attack for all combat, why the others attack dont touch; plus i m hitted like for blackjaw, even when im far away of the attack and i successly anticipated.
Its not like that you make a game difficult, your IA is always cheating as (improving its speed mvmt and attack, most of the times at the end of combat, making a move or a hit normally impossible)
Vry disappointed by how you try to make the game difficult, its cheat and bad design