255 vit/spirit is pretty much a must for Minerva so her attacks don't one shot you, plus guarding when she does Ultima. Judgment arrow can suck too, cancels reraise among other things plus drain MP and AP.
Ziedrich is a must for that fight too, least imo for the 100 increase to all stats minus luck, it's in a chest in mission 9-5-6. This coupled with a materia with +100 spirit and one with +100vit will give you 255 of each.
And need something that does 99999 damage else you'll be in for a long fight, and even then it takes 99999 X 101 (at the least in normal mode) to win, more with her healing moves.
As for other genji equip(and I'd suggest armor/shield/gloves/ziedrich for this fight) for genji armor get 100% DMW for each character, meaning see all the little videos, there's a summon you can miss permanently though and won't be able to get armor. Auto Regen/Auto-Endurance(moves won't knock you back), plus break HP limit.
Helmet find the shop card in a chest in 9-5-4 then buy it for 1million gil, can only buy one, unless you buy them all at the same time, if you close it and reopen the helmet will be gone after you buy. Although this gives 0 MP and AP cost, I still wouldn't use in fight over zeidrich, just pop an elixir+phoenix down after Judgment Arrow and heal up, good to go, dualcast is good also.
Shield is the magic pot in 7-6-6, do the moves it asks for (Gil Toss, Costly Punch, 99999 Damage and Octoslash) and if you already have the Item Mugger materia for Magic Pot DMW, it'll give you the shield, this and armor are the worst to get imo, can take hours to see all scenes and hope Octoslash activates before the pot runs away. It grants auto wall(barrier/mbarrier), absorbs all elemental attacks and cancels all bad statuses, but since she doesn't use any, it's just used for autowall in this fight, can also use a protect ring for that effect.
Judgment Arrow can't dispel auto-effects, so those are key to this fight.
And Elemmire, those 2 are from the cellphone title Before Crisis,