This method tested and works in the Steam version.
As you might have noticed when you kill a boss monster you get only 30% information on it and in some cases it's even 15%. If you fight them fair and square then you'll have to play through the game up to 7 times to get them all. Kinda a lot, don't you think? It's not like you have to since only a few bosses in the game are worth it and you still have to play it at least 3 times to get all the endings, but honestly 7 playthroughs?!
You know what? You don't have to!
This game saves progress in an odd way by saving state and collectibles separately. Now, you might probably heared about the metod to save your game in the different slot, reloading the old one and go fight the boss again. Forget about it. It doesn't work in this version of the game. However, if you add one extra step it will work again!
- Save the game before the boss fight. Usually there is a save point right near the boss.
- Kill the boss.
- Save your game in the different slot.
- Load your game from that different slot. ← Here, extra step.
- Load your game from the initial slot. ← You may go to collectibles to check at this point.
- Go to second step :)
Obviously this trick works just as fine with respawnable monsters, but why would you do that?! You can respawn them just by going to another area and back.
BTW, all character achievements are carried over too. So, you may approach the boss in the different way with a different characters and get some personal achievements with it as well.