Let's Play 7th Fantasy (Kuja) Episode 27: Baran Castle @ Level 23

In this playthrough, our high Speed and FAST spell allows us to take on Baran Castle at level 23 without much trouble. It's important to bring along a few Harps, though - the Black Knights' XXXX spell (aka Vacuum 2) could otherwise wipe out both party members instantly. The Amulet, found behind a pillar in Bilthem Castle, is keeping Kuja safe from Death-elemental spells anyway - so only Robo will be consuming Harps - and unlike the Rub spell, with XXXX you have no idea in battle if a Harp was consumed because the "Harp Prevented" caption doesn't come up. Check your inventory from time to time!
Oh - and at level 23 Kuja learned the Flee spell - which for a horrendous 40 MP guarantees an escape from any non-boss battle. However, his Speed is high enough that I'll probably never need to use it. I may demonstrate it once or twice, though, just to show how it works.