Auto Level XP / Materia (AFK)
Here’s an easy way to cheat the DMW system and level your Materia and Zack up without grinding.
Moderate leveled character, I was lvl 15 when I tested this. I also recommend a setup with Materia like Assault Twister with +60% HP to ease things. High Vit Accessories help too.
Use Mission 1-1 Training where you fight about 6-9 basic Sentry Soldiers. They do very little dmg. Switch you guard button to RT/R2 and use a rubber band to hold in place. Let the peons attack you endlessly and they generally will do 1 dmg per hit.
With a lot of SP the DMW will spin forever and the chances of getting more HP is pretty good to the point I finish with more HP than I started with. This gives the DMW a chance to hit the Materia LVL+ and 777 rolls many times before you manually finish the fight.
Thats it. Since its random to lvl up most things and if you have a lot of invisible XP stored up, and great chance to 777 for actual levels.
AFK for a half hour or more and keep an eye on you HP while you do something else and save the manual grind.