Im at a loss with Kukki-Chebukki

[Morovich]

How is he supposed too work, webpages say he casts all these spells and such, but I was told its only based on day and enemy elemental resistance, I mean he just stand there doing nothing but cheering from the sidelines as it were. If it's based on day and resistance how do I utilize him effectively i.e. know when he will cast spells or not?

[Urthdigger]

I imagine he only casts spells that match the current day or weather, but will refuse to cast if it'd be bad for you. Unlike Shantotto who will gleefully casts water spells on mobs that absorb water damage >.>

[Vinedrai]

How is he supposed too work, webpages say he casts all these spells and such, but I was told its only based on day and enemy elemental resistance, I mean he just stand there doing nothing but cheering from the sidelines as it were. If it's based on day and resistance how do I utilize him effectively i.e. know when he will cast spells or not?

You must have called him on lights or darksday. On those days, he is pretty much useless since there isn't any elemental magic associated with those days. In my experience, he doesn't do anything on those days.

On any other day, he will exclusively cast elemental dot and nukes based on the current day.