Please, hack my account

Themida's checks

Just to clear a random misconception; Themida is a PE (portable executable, not packet editor) packager, not an anti-hacking tool. It's the executible equivalent of a zipping the binary so it's harder to reverse engineer, it's passive and doesn't "check" anything, simply obfuscates, or tries to. UnThemida and various other tools can dump the raw executable as readily as from a zip file too and leave the application wide open for exploratory reversal.

I think he's saying modify the packets(?)/data to enter your PIC for your character, but log into a different character. It checks for a correct PIC of character A, but then you force it to connect to character B?

Actually it was proven in the past you could just NOOP past the pin check and have the pseudo-client just skip straight to the world select. The PIC is different in that it occurs further down the chain and prevent access to individual characters, instead of the account itself, so it's uncertain whether a modified client could successfully bypass it, or would fail authentication where the PIN did not.