Complete Save Bonuses
In Xenosaga, possessing Game Clear data from Episode I when starting Episode II gives your entire party the ability “Swimsuit”, which dresses them up in swimsuits of various appeal, but more importantly is one of the only ways to boost your Speed, and can’t be obtained any other way. Game Clear data from Episode II to Episode III also unlocks a couple new costumes as well, such as Shion’s Vector uniform from I/II, which are again otherwise unobtainable. Both game’s save data also allow for a bonus in starting XP and skill points for characters in the next game, though the benefits are severely curtailed; maxed-out levels in the first game will add perhaps 4-5 levels to your starting total in the second.