RPG Insanity

Hi, I am new to this forum and almost at the end of this game. Lucas, Iria, Melvin, and Elodia are close to level 60. Their jobs respectively are lionheart, neo- dragonite, brigand king, and sorcerer. I already  got creamed three times by the red dragon. My question is what are the suggested levels and strategies I should use for red and Shrine Guardian entrance dragon. Do these bosses have any weaknesses?

I know this is an old post, but I figured I'd answer anyway.  It sounds like you haven't been spending your LP's, either that, or you haven't been spending them on EP seeds.  Just buy the most expensive EP seeds - each one will give all party members like 50 EP.  Then you can max out your growth plates.  You're not really cheating by doing this - the game is designed for it.  There's a bit of end game content that would be more or less impossible without spending your LP's.  You can access this shop from your status menu, lower right-hand side.

Best way to earn EP is farming Metal Enemies at high Floors of Goddess Castle (even low floors give more EP than anywhere else). You can beat the game without spending anything on IAP shop, the only requirement is high enough Level and Character Job development for all passives.