Everything we are told about Voldemort in MoR (at least part of which comes from reliable accounts) matches canon Voldemort and suggest an equally cartoonesque villain composed mostly of questionable motives, self-defeating pettiness and pointless cruelty, with zero PR skills and awful fashion sense, not to mention a certain fondness for the Idiot Ball.
Except we also have Dumbledore describing V as clever like Harry, or words to that effect. The two monastery stories seem consistent with this: first of all, canon!Voldemort would never have sought out a Muggle teacher at all. Second, the two stories together suggest that MoR!Voldemort got what he wanted and then returned without his disguise to get revenge, like he said Harry would do if Harry became like him. Also, what orthonormal said.
Edited to add: and come on, we know MoR!V killed Narcissa Malfoy. Draco told us himself to look at the result and ask who benefits. The plan surely broke an evil overlord rule or three, at least in spirit, but if V couldn't get Lucius on his side he probably needed to kill the default leader of the pureblood faction anyway. And V, as a skilled Legilimens, could probably count on Lucius responding irrationally to his wife's death one way or another.
[Update: and now there's a fifth discussion thread, which you should probably use in preference to this one. Later update: and a sixth -- in the discussion section, which is where these threads are living for now on. Also: tag for HP threads in the main section, and tag for HP threads in the discussion section.]
The third discussion thread is above 500 comments now, just like the others, so it's time for a new one. Predecessors: one, two, three. For anyone who's been on Mars and doesn't know what this is about: it's Eliezer's remarkable Harry Potter fanfic.
Spoiler warning and helpful suggestion (copied from those in the earlier threads):
Spoiler Warning: this thread contains unrot13'd spoilers for Harry Potter and the Methods of Rationality up to the current chapter and for the original Harry Potter series. Please continue to use rot13 for spoilers to other works of fiction, or if you have insider knowledge of future chapters of Harry Potter and the Methods of Rationality.
A suggestion: mention at the top of your comment which chapter you're commenting on, or what chapter you're up to, so that people can understand the context of your comment even after more chapters have been posted. This can also help people avoid reading spoilers for a new chapter before they realize that there is a new chapter.