Sarda exists in six different directions of space at once: what happened?
 

Sarda is supposed to exist in six different directions of space, why is he suddenly coming up dry now?

Because maybe he wasn't telling the whole truth? Just because someone says something doesn't make it true.

Definitions
 

Also, it depends on what he meant by "six different directions at once". If he exists in three dimensions (or directions) than travelling foreward and backward (time travel by itself) would validate the statement. It's more likely that a) it's something more arcane and obscure, b) he was lying, or x) it's funnier this way (and he did it to himself, being the wizard who did it).

You could say we all exist in 3 directions in time (forward, backward, and no direction), which would make his statement true (because with young Sarda still being in the same point of time the amount would double). However, it still doesn't really work within context plus with the directions given in the title (although titles are just gags). The last panel in 496 makes me think that his non-linearity is something he can turn on/off, or perhaps just look around time like a telescope (chronoscope?) but not see all of it at once.

More likely than not, a wizard did it.

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I like the way you phrased it better!

I assumed he could see the past-present-future of both his selfs, ergo 6 directions. Didn't seem like he lied to me. I suppose that technically it's 5 directions now with Onion Kid gone - still true the present of when he said that!

It would still be 6, since, presumably young Sarda/Onion Kid was only teleported spatially and not temporally.

mmmmmmmmmmmmm maybe six directions means he sees things from 6 diferent perspectives... at the same time.

He is probably insane because of that (I mean, c'mon if your brain could receive past, present and future at the same time how else could you feel?)

Or maybe Sarda's just a liar. We know he is really powerful, but since he has outright lied to the Light Warriors before (especially Black Mage) just to mess with them, I wouldn't trust everything he says.

Or maybe "six different directions of time at once" is just a phrase chosen to express that Sarda routinely works in areas of knowledge other people can't begin to comprehend and doesn't allow for any precise definition.