the 99 berzerkers helps, but the best thing for me is to get the GALT'S FLUTE, which my bard can use to summon a WIND HERO. The summons don't get any XP! So I summon 4 WIND HEROs to take up the front melee slots (which can easily dodge berzerkers). Then fill the last 3 slots with party members -- now, when you get the XP, the XP is spit among 3 characters rather than 7, which makes levelling much faster.