How to use the Clayman's Harpoon?

If I'm going for pure intelligence, should I use magic affinity, ice affinity, or go standard while enchanting with a scholar's weapon?

Based on my tests, the scholar's weapon and the cold infusion caused more damage, with the former being twice as strong as the latter, and the latter twice as strong as the magic infusion. Magic infusion and standard infusion dealt the same damage.But in my tests I had high dexterity and intelligence, and the weapon was at level 0.