Did you know there were reportedly 5 wizards sent to middle earth, but two were slain by a dragon that rhadagast the brown only barely survived and lost most of his wits to?
you probably did, but i thought i'd mention it anyway
As far as we know, no one knows what happened to the other wizards, known also as the Blue Wizards. I'm not sure where you are getting your information from. But I have a passage from the Unfinished Tales which tells of the these unknown wizards:
"the two other 'Blue Wizards,' unnamed, who passed with Saruman into the East, but unlike him never returned into the Westlands." (Unfinished Tales, p. 507)
Another interesting quote elaborates with a little more detail about the Blue Wizards, even giving them names (a pretty obscure and unknown fact):
"Whereas in the essay on the Istari it is said that the two who passed into the East had no names save Ithrin Luin 'the Blue Wizards' (meaning of course that they had no name in the West of Middle-Earth, here they are named as Alatar and Pallando, and are associated with Orome, though no hint is given of the reason for this relationship." (Unfinished Tales, pp.509-510)
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