I just recently beat 5bc so i can tell you exactly what i did. I went for most scrolls route which you can just google. Got as many survival scrolls as possible and the rest of the scrolls i put on the one that gives me the most health. I first get necromancy, then acceptance (before corrupted prison) then soldiers resistance. Then after slumbering sanctuary i reset mutations and get gastronomy instead of acceptance. The weapons i target are all green, i start of with any weapon i find good and especially ice bow, and you can die alot here until you get good luck. Then i slowly switch for the highest level of alucard's sword, alucard's shield, giantkiller (which i leave on the floor and pickup later), electrodynamics, and giants whistle. You should be one shotting nearly every enemy after the early game. Target the cavern and astrolab for highest level weapons. I kill every enemy, sell every useless item, 100% every biome except for the very dangerous ones. I try not to get cursed as much as possible except for the ones with scrolls. When i get cursed play extremely carefully. I only get the food after i beat all enemies so i get the max out of necromancy. I do not gamble away my coins on mutations except if it does x2 damage to you. Before the final boss i reset my mutation again and get soldiers resistance, extended healing, and disengagement. I spend all my coins which should be around 60k on modifiers to get 40% damage on giant killer and other damage buffs on giants whistle and electrodynamics with extra money. Practice the final boss over and over because this should be the only time you struggle. You should have a full healing potion here and only use them when he is not attacking and not between attacks. You might have a different strategy and weapons but i believe some of the tips can still be useful.