Aw man, I've never even put him into battle since he started at level 1 and didn't feel like leveling him.
Oh, you're fine then. As mentioned, the transfer effects only occur if Sothe reaches Level 20. If you never use him, that won't happen, so he'll have his RD bases.
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xp1337: Don't you wish there was a spell-checker that told you when you a word out?
GotD (219/384) Melee v FFX