Nefashu question and -1/-1 counters

[Jiki]

If I attack with Nefashu and there are less than 5 creatures, can give more than one -1/-1 counters to some of the creatures?

[Kenji]

Nope, as Nefashu isn't worded that way. When its ability goes on the stack, you select up to five creatures, and each of those gets -1/-1 until end of turn. That's it. If you were able to "distribute" the leftover -1/-1, it would be clearly worded to allow for it -- it isn't worded that way, however, so you cannot. Here's something from the Comprehensive Rules that should help:

114.3. The same target can’t be chosen multiple times for any one instance of the word “target” on a spell or ability. If the spell or ability uses the word “target” in multiple places, the same object, player, or zone can be chosen once for each instance of the word “target” (as long as it fits the targeting criteria). This rule applies both when choosing targets for a spell or ability and when changing targets or choosing new targets for a spell or ability (see rule 114.6).

So, if the ability was worded like this, you'd be able to target the same creature more than once:

"Target creature gets -1/-1 until end of turn.
Target creature gets -1/-1 until end of turn.
Target creature gets -1/-1 until end of turn.
Target creature gets -1/-1 until end of turn.
Target creature gets -1/-1 until end of turn."

Since the actual wording of the ability uses the word "target" only once, you can't choose the same target multiple times for Nefashu's ability. Also, Nefashu doesn't give counters; it's merely a -1/-1 that lasts until the end of turn. When something places counters, it'll use the word "counter" in its text.