Seriously in example sentence
The flimsy plot isn't meant to be taken seriously - why else make Merlin a heavy when in most, if not all, of the other versions he is more a friend/mentor to Arthur - so if you start wondering aloud why Sir Lancelot who has been sold to historians as the epitome of chivalry and uprightness metamorphoses into a schoolyard bully you're not going to get much fun out of what is essentially a fun movie.