The question is pretty simple actually, though I have trouble deciphering the features of the Duskblade class from PHB2. The arcane channeling of level 3 allows you to use a standard action in order to cast a touch spell and deliver it through your weapon with a basic attack, that much is clear.
However at level 13 you gain the ability to cast the spell as part of a full-round attack and "the spell affects each target you hit in melee combat that round". What is not made clear and I would like to understand is this: If you hit the same target two or three times during a full-attack action, would the target be affected more than once by the channeled spell (e.g. scorching ray)?
Best Answer
Yes.
The wording is a little suspect, but that's par for the course in 3.5. Think of it this way; each time you attack an enemy, you target them. Each act of targeting gives you another opportunity to use your Arcane Channeling spell.
You could easily argue the opposite interpretation, but the class doesn't seem to be designed that way. Most of the class design, spell list, and Playing a Duskblade section emphasize how they fight against single melee targets, which makes me think that the level 13 ability wouldn't make a lot of sense if it were only useful against multiple targets.
What's more, I've seen it played as a way to attack a single creature with a spell multiple times, and I never saw any balance problems with it, so it's probably fine to play it that way.