I think for Magical Accuracy, they may have to use some sort of fruit maybe, not fish. The reasoning for this is because of the Black Mage foods now are mainly Fruit Pies (Melon Pie, Rolanberry Pie, etc)... but then again, resists are based on Mind, not Intelligence.
Maybe Mushroom Sushi* could have Magical Accuracy (*that is, if they make a mushroom sushi recipe)... the mobs MND level effects resists, so I could see how Mushroom Sushi could give M.Acc+..
However, I do not wish to speculate further, but ThunderGod does have a good point. I know a lot of Black/Red/White mages will love to have some M.Acc+ food, more so for endgame, BC, HNM, etc before they can Merit spell potency etc.
MND does effect resists. It's why magic doesn't work as well (most of the time) on mage type mobs. Though, MAcc+ would probably be frp, some kinda new fruit vegetable hybrid thingy. o.O Just a thought.
INT is as follows for those that want accurate info:
A stat that helps determine the effectiveness of Elemental Magic spells, Black Magic Enfeebling Magic spells, Black Magic Enhancing Magic spells, Ninjutsu and Icebased Blue Magic. Intelligence also affects the rate at which offensive spells are resisted (see resistance) and the damage taken from most magical attacks. Intelligence also determines the additional effect from Earth Arrows, Water Arrows, and Wind Arrows. Intelligence also increases the chance of taming an enemy.
Did you ever think that most mage type mobs have "Magic Def. Bonus"? Also you seem to be thinking of potency. MND will affect the potency White magic, and INT will affect the potency of Black magic. I have yet to see any valid proof even suggesting that they effect resist. So, until then I will believe it doesn't.
That being said your a complete fool if you dont believe what i posted verbatim, which is also verbatim from SE.. Hey it's up to you, i wont twist your arm and force you to belive, but facts are facts though, and you clearly have yours confused bud...
id guess magic doesnt work well on mage type due to "Magic Def bonus" trait that whm and rdm get. I dont know this for certain, and its just a guess.
I do know, INT affects potency of nukes and potency of the BLM/RDM type enfeebles, and as a result, i would guess that MND affects potency of WHM/RDM type enfeebles and cures.
But to the OP, as a 74 RDM, i sell my goldfish to SE for some M.acc food. I like INT food, but id prefer nukes and enfeebles to land unresisted before i try and beef the dmg done by nukes. And i would hazzard a guess that M.Acc is better than INT, just like Acc is better than DEX (for trying to hit), Att is better than STR (for hitting harder - not WS). Ofcourse, i wouldnt turn down a MAB food either >_>;
I've been looking for info on this item for awhile, I fished up 3 stacks like the first week ToAU came out and ended up just NPCing them cause no one knew what they were for.