Are all the hardest battles in grand duels specifically made to use command seals or what.

I used King Hassan to defeat him and I still lost for the first time because of the 1 turn insta kill and the dot damage. He was unkillable and I cant wonder how someone could insta kill him eight times without dying by this mechanic.

Every final grand duel featured mechanics that absolutely destroy the player no matter what and he has to use command seals.

F2P by the way, so no np 5 damage or lvl 120 power here.