help me with my new chronicle please

I have started an adventure. An aspiring wizard travels Middle-Earth, finding diverse company along the way, searching for lore and wisdom. As he gets wiser and more powerful he discovers a rising evil.

Thats the quick overview.

I am having trouble deciding who the rising evil is going to be. It is set in the fourth age, so I could go with the commonly used Blue Wizard gone bad approach, but I wanted to work into my chronicle that the reason he is trying to become a great wizard is beacause the 5 have left. Any ideas on what I can do?

good premise, if you assume that anyone can LEARN to be a wizard. The 5 were sent to M-e, remember... they were divine or semi-divine, cast into mortal (or semi-mortal) bodies. Anyway, somehting like that. Actually, you could do somehting with that - maybe the "rules" have changed, now that the ring is destroyed and the wizards are no longer needed?

also, maybe the word is that all 5 have left (ala Gandalf) or are dead (Saruman)...but ACTUALLY, one of them remains! Why? What's he up to? This straggler could become the young wizard's nemesis. You could slowly build to a final confrontation. The blue wizards went east, so there's loads ot play with there, story wise.