Board Thread:Rewatching "Merlin" - Season Five/@comment-5102537-20140426100805/@comment-24785400-20140506114223

Merlin was cut in the S1 - side-effect of making him younger(and he lost his ability to see future) before losing all that remained in S5 

I think you're  so right with this. It seems to be that they stripped Merlin of all his characteristics that make him the Merlin in the legends. Its OK to do this if you are going to have him become that character in the end, this is, after-all supposedly a  "before they were famous" take on the story. But what they've done here, is give those characteristics to others and left him with nothing. So Merlin is known in the legends, more than anything, for his gift of sight, and making prophesies. He never gains this gift. Morgana (who is never known in the legends for having the gift of sight as far as I'm aware) gets this. The Dragon is given the job of telling Merlin what the prophesies are, he can also see into the future. Gaius is the wise man, with knowledge of the healing arts (another attribute that is often given to Merlin), and also adviser to the Uther, and later Arthur. Merlin is merely as servant who Arthur sometimes listens to. Morgana lives in a hovel in the Valley of the Kings. Merlin of legend never resides at Camelot. He lives in the enchanted forest (those who want his advice have to seek him out). Merlin of legend creates the Round Table (which comes as a wedding gift from Guinevere's father). We have to assume the round table here was Arthur's idea. Merlin of legend tells the Arthur and the knights to go on quests, (to seek the grail), and often gives them warning. Merlin here is always reacting to events. Even if you were to take Mary Stewarts Crystal Cave as an example, we only get 2 instances in the entire run of the show where he goes to the cave. Everybody else knew what was going on more than he did. The one thing truly different is that in the legends he often advises Arthur against marrying Guinevere, here, he is actively pushing it. So we're left with Merlin creating the sword (in a different way) and plunging it into the stone, and being a Dragon-Lord (not something in the legends, but he was often seen as only half-human, so its sort of comparable). Even the coda at the end. There are so many variations in the legend - that he's sleeping on Barsley Island, guarding the Treasures of Britain,  that he is in a glass castle, a cage or under a hawthorn bush (a gateway to the otherworld), depending on whether Nimue/Vivianne is written as loving or not. Instead we see him wandering around, endlessly waiting miserably for Arthur to re-appear. There's nothing on screen that we see to show that he's become the legend.