Look for forums or communities dedicated to Kingdom Hearts and Cheat Engine. There are often pre-made tables (cheat files) that can enable infinite Limit Breaks, among other cheats.
Instead of just high-level characters, focus on building a team with complementary skills.
As soon as the player clicks a button, refreshes the page, or engages in a battle, the game forces a synchronization check with the server. The local memory is overwritten by the server's correct data, and the resource value snaps back to its original number.