I've been practicing this game getting ready for a new game run. Having a few problems with the final boss.

Does anyone have any tips?

I am using Hero, Kika, Sigurd and Jeane. Just standard runes and basic equipment so as to save time in the run - and weapons are strengthened to 9 (except Jeane who is 1) so as to limit potch grinding.

If I level on the final stairs to 57 - I can beat the boss sometimes, but it's not super reliable unless I return to the ship to spend the potch gained on jizo clocks.

Any advice welcome, thanks