You get an accessory that gives you so many status', break HP limit, break damage limit etc.. but it curses you as well. If Minerva is your last mission, and she probably will be, you get Divine Slayer as well which does a tad less than the above but doesn't curse you.. much better prize I think.
*looks up exact details*
Divine Slayer: HP, MP, AP + 100%; Max HP, MP, AP = 99999; Raises all stats by 50.
Soul of Heike/Heike Soul - HP, MP, AP limit = 99999.
- Absorbs damage from all elements.
- Gil & Item received from enemies x2.
- Has effects of Thief Glove, Knowledge of Healing,
all "Impact" accessories, Item Master materia,
SP Master materia, & Double Cast materia.
- Enables Auto Scan, and also inflicts Curse