I'm not sure if there is a fanfiction specifically with that title that is appropriate for all audiences. There are many fanfictions out there, but this description sounds like it could potentially involve inappropriate or non - family - friendly content. It's important to look for fanfictions that adhere to ethical and respectful standards.
Their relationship could develop in a complex way. If Morgana ties up Merlin out of anger or suspicion initially, but then realizes she was wrong, it could lead to her feeling guilty. This might make her more open to Merlin's friendship in the future, and they could gradually build trust.
In a more humorous take on the 'Merlin tied to a bed' fanfiction, it could be that Merlin has fallen ill and the overly - protective Gaius has tied him to the bed to make sure he rests. Merlin, being the active person he is, complains constantly. Arthur comes to visit and teases Merlin about finally being still for once. Meanwhile, Merlin tries to convince Arthur to let him loose, promising that he'll be fine. Eventually, Gaius relents and unties Merlin, who then immediately starts bustling around the room.
One great 'Merlin Morgana fanfiction' is 'The Bond Beyond Magic'. It delves deep into their complex relationship, exploring how their powers could have been used together in a more united way against the common threats in Camelot. It presents a unique take on their dynamic, showing that they could have been allies instead of adversaries.
One great Merlin and Morgana fanfiction is 'The Enchanted Bond'. It delves into their complex relationship in a way that stays true to the characters' personalities from the show. The author does an excellent job of creating a believable world within the fanfiction.
One more idea is that Merlin is tied to the bed in a dream - like state created by an ancient magic. In this dream world, he is faced with his deepest fears and insecurities. His friends in the real world notice his strange behavior and try to wake him up. Merlin, while in the dream, has to find the source of the magic that is binding him and break free. Through his inner strength and the memories of his friends, he manages to do so and wakes up, having learned more about himself and his magic.
One possibility is that there would be a great deal of tension. Old Merlin has seen so much and has his own wisdom, while Morgana has her own powers and motives. Maybe Merlin would try to persuade Morgana to abandon her dark path. He could use his experience and the bond they once had to appeal to her better nature.
She might be shocked at first. Given that in the original story Morgana has her own complex relationship with magic, seeing Merlin's magic could stir a mix of emotions in her, like envy or a sense of relief that she's not alone in her magical abilities.
In fanfiction, Evil Merlin can be depicted as a mastermind behind many dark plots, while Morgana is the face of the chaos they create. For instance, Merlin might be the one secretly pulling the strings, using his magic to make things happen, and Morgana is the one out in the open, using her charm and power to intimidate others. They are like two sides of the same evil coin, complementing each other in their wrongdoings.
Redemption is also a common theme. Since Morgana often takes a darker path in the original, many fanfictions explore the possibility of her redemption, with Merlin being a key factor in that journey. Love, in various forms, is another theme. It could be a platonic love born out of mutual understanding or a more romantic love that defies the odds.