Cat and Mouse
Did she really think she had him fooled? Merlin couldn't help but be amused at her confidence in her own powers, much like a child who has just learned how to read and desires to show off their new skill to everyone, and like a proud parent he had smiled indulgently and gone along with her little display. Although he had to admit his feelings towards her could not be further than those of a father to a child.
She thought she was in charge of this game, a cat playing with a mouse. What she didn't realise was that this mouse hid a far darker and dangerous entity. Uther's lackey? No, not quite. He did admire her attempts though, he hadn't expected the drugging until he felt himself being affected. It would have been simple enough for him to burn it out of his blood, his magic had sang for him to do it, to teach her not to play with fire, but curiosity had stayed his will. He wanted to see what she would do. He had been more than a little disappointed to find out that not only was her magical repertoire limited to shape shifting but she had him tied to a bed and had not taken advantage of it. It had been the only reason he hadn't just burned those flimsy pieces of rope, well, that and he had never been a fan of showing his hand to an oblivious opponent. If she wanted to believe he was weak then he would allow her to, as long as it was convenient for him.
Now she was not pretending to be a child but Igraine. Shape shifting was considered a powerful art, but for someone of Morgan's abilities, abilities that could almost rival his own, it was a paltry parlour trick. So much untapped potential, it was a shame she squandered it so when he could teach her to move mountains, bring lightning in a cloudless day, control the earth itself, everything and anything. But that would have to come later, after this whole mess with Albion had been sorted. He had already seen the end and he hoped she would survive it.
That was for the future, currently he had more pressing tempting issues to deal with. He wished she would have chosen a woman other than Igraine to parade around as. His more human side was guilty for inadvertently forcing the woman into a marriage she had not wanted but his magic side, that seemed to be growing more powerful as the days passed, despaired of Igraine. Had the foolish woman not yet realised that she aged and he didn't? That her lifetime was but an insignificant blip on the vast expanse of his own experience and thus that pursuing any kind of romantic relationship with him was an extremely bad idea. Morgan, on the other hand, though she had not yet realised it was not that different from himself, but soon (his perception of 'soon' anyway) she would know. When her allies aged, grew grey and died yet she would remain the same, untouched by the passage of time, she would then know true isolation. She thought herself alone now, she had no idea. But she would. And when she did, he would be there to guide her.
It was this that kept him from killing her, even now when she was trying to find his weaknesses wearing Igraine's face, he so badly wanted to remove the life from her and watch that smug smirk fade as blood pooled around her. She may have only been a slight inconvenience to his plans but she was an inconvenience all the same, and a distraction. He wanted her. Gods he wanted her. It wasn't love, he wasn't sure he was even capable of experiencing such an emotion, not since his family had died. But it had been a while since his magic had ached to be bonded to another's, when was the last time? Nimueh, thirty or so years ago. Or had it been longer? Perhaps Morgan would now have the confidence with the illusion of Igraine as a shield to do what she had not been able to do before.
So, as before, he would let his curiosity lead him and play along with her little game.
AN: This is going to be a long note, I have quite a bit to say. First, this can be read alongside my other 'Camelot' one-shot called 'The End' but can also be read separately. If you do decide to read them together, read this one first. Secondly, my interpretation of Merlin is based on my unwavering belief that Merlin is a total badass immortal sorcerer and so I highly doubt Morgan would be able to trick him with so little experience also the whole 'cat and mouse' thing is based off what Eva Green said in an interview when she said that Morgan liked toying with Merlin like a cat with a mouse. Finally, and this is just targeted at Merlin/Morgan fans, if you have not read 'Dawn of Avalon' by Anna Elliott, I recommend it. It's a short story, and is usually free, just search for it on the Internet (also if someone wrote a 'Camelot' fanfiction which was a rewrite of the series using the thing that Merlin promises Morgan near the end of 'Dawn of Avalon' I would be very happy *SPOILER when he promises to protect her*).