Can't believe I fell for this bait. Been farming for almost 5 hours and still am no where near close to being able to defeat the first boss.
Jesus. I did mention to start on Crysis... but after you get familiar with in-game systems and mechanics.
All you need to beat first boss is level 8-9 (maybe even less if you're lucky), which is like ~30 mins of farming.
At this point you should have Dark Magic 2 (from increasing corruption to 15) and Dark Bullet should 2-3 shot the two tentacles during the boss fight. You have to hope for RNG so you won't get grabbed while tentacles are still alive - once you kill them, it's an easy win. It's just smack & heal with the boss once tentacles are dead- just keep your HP high in case you get grabbed.
If it's still too hard, get upgraded weapon. Radical Gear (magical suit customization) is pretty neat, too (20% dodge chance).
Get healing engrams - they increase the amount of souls you get from purification (less farming). Attack mobs from behind for free turn. Get early items from shops in the city (headband and earring). Buy foods in convenience store for MP recovery outside combat so you can spam Dark Bullet and farm efficiently.
First boss is the hardest and the most boring part. After that you get side-quests to farm souls and Dark Bullet will kill whole groups with 2 shots. Be sure to increase AGI and max HP at the school every day.
A bit later you can get MP regen after combat from corruption gear and attack that recovers MP from Close Combat engrams so have unlimited MP (with gear that boosts SP recovery). Then you get corruption gear with regen in combat and last healing engram with does the same thing and this will make you nearly unstoppable (upgrade your gear along the way).
If you want to be even more efficient you can get elemental magic and weapons once you learn enemy weaknesses. Buffs and debuffs are strong, too. But Healing, Dark Magic and Close Combat is all you need to beat the last boss on Crysis.
That one annoyed me too, i found out after a bit of fustration:
If you have glasses from train side-quest in chapter 2 you will just see the corridor. You should keep them on anyway so you can find secret bosses in some dungeons because they drop very good gear.