Crisis Core Reunion - SP Master/Gil Toss/Costly Punch showcase (Minerva Fight) [Final Fantasy 7] 

The strongest offense and defense is Gil and SP. If you don't know what's going on:
SP Master is tanking every bit of damage using SP
Gil Toss when Costly Punch is out of range. I used it very sparingly since I don't want to use up all my Gil and it gets weaker over multiple usages
Costly Punch and Curaga to loop the 99999 damage
There are tons of guides out there on how to get the build I'm using but only the OG PSP Crisis Core videos highlighted the potential of these skills. NOt to say there's no one doing it or it's not known but the most viewed videos are aiming for early clears so they only show you how to Costly Punch Minerva 100 times.