RPG Insanity

It's been a long time since I played this game, but thinking and looking back on the method of boosting stats (STR, INT, SPD, VIT) by using spirits, I feel it's not the most sustainable way to fight bosses. I dug deeper and found there are permanent stat increase items - All gain, STR Flesh, Vit Flesh etc.

These Flesh items can be bought from the Shop as IAP items. All Gain requires 200 GSP, which means per purchase needs 600 battles (1 GSP per 3 battles) and that's not an efficient way of grinding. Is there a location to buy these (like from Forgotten Village in other games) or other ways to get them? Maybe I missed something...

Hm, you probably could try that fairy portal or something... I've played the game without using them ^^' After I got the EXP bonus, I could beat Dark Savior with levels and some items alone...

You can get one or two fleshs there, but that's pure chance.
You can also obtain some stat-enhancing items there too (forgot the name, the ones you put on the weapon). They're very effective at 100%