ya pretty much, theres acctually quite a few that everyone learns, not just battle skills either, stuff like double jump, or ariel dodge... stuff like that. Although every character learns all the battle skills by pretty much lvl 50. Terra learns blizzara, thundara, gravaga, blizzard (combo), tornado, flare, fira, meteor, holy, and ultima (but only can use ultima if it manages to chain holy and flare together, but boy is it worth it if u do)