Both are such betrayal that I will never forget! It makes me go on Morgana's side even more. Everyone betrays her! And how could Mordred forget all Morgana did to him? Arthur saved him once, yeah so did Morgana, Morgana did more to save him. Mordred was just supposed to be the one that would always be loyal to Morgana no matter what, and then he betrays her just after they reunite? So disappointing

I understand Mordred, he took a stand when he saw what she stood for. He saved Arthur from being killed directly by Morgana.

Merlin tricked her, poisoned her and she had done nothing wrong.

None!!! Merlin had to poisoned her to stop evil creature and future evil which Morgana will make!
I respect Mordred's actions ! Yes, he stabbed Morgana, although she was his saviour but Arthur and Merlin also were his saviours!!! More over Morgana showed herself a bitch again!!! Arthur was very brave as always!!! He wanted only thing - find and save his people from her slavery. Mordred made a right decision!!! Although exactly he is bane of Arthur Pendragon!!! So, Mordred has some plan I wish I know....

I don't respect Mordred at all. he has no loyalty.

Mordred stabbing Morgana was cruel, though Merlin poisoning Morgana, his very close friend, was crueler. Mordred was just a little boy she saved, the fact he came back & betrayed/stabbed her, wasn't a good way to pay her back for all the good she did to him, & he was all she really had, though the reasons he did it were understanding, he realized she was evil, trying to kill the king, & decided to betray her for good & stay by Arthur, though i do have a feeling that was all just a trick to get him on Arthur's good side so he can kill him himself, though Merlin on the other hand was a very close friend she could trust, him trying to kill her is one of the reasons why she is the way she is, getting abandoned by every one she finally gets close to, though i dont really blame him, it was the only way to stop the future from the evil she would make, though he had lots of guilt doing so.

both were extremely cruel!... Everyone betrays Morgana that's one of the reasons I can't help but to only route for her

I never apologize Merlin after this