For the purposes of farming level 5 petrify, get Final Sting and equip it.

Get to the final boss, take her down to 30% so she summons the adds, take the Manor Sentry (the ahriman) down to 20%, wait until it casts it then kill it.


If you do not learn it, just Final Sting one of the other adds to die and restart the fight to try again without having to do the dungeon again.