-When you find a save point, avoid it. Instead, first kill all the enemies ahead. After you are satisfied with the amount of enemies you have killed, backtrack to the save point that was skipped and hit it. The game records your current lore level at this point. After that, once the save point is hit, kill yourself. Therefore when you regenerate at the save point, you will have the same amount of lore. All the enemies that you already killed will return. Kill them again and get even more lore. The Relic Boxes also work in the same way.
-Note: Do not max out Kain's lore (blood bar roughly the same length as lore bar and lore bar full). If this is done and the game is saved, Kain's blood bar will revert to nothing. If this happens, a simple jump will cause Kain to die. If you kill all available targets (including humans) throughout the game, you will get the same blood bar level as you would using the trick. If you do use this trick and are nearly maxed out, stop drinking blood and opening relics. Otherwise, you will lose all your hard work when you save.