Honestly, the second battle's not so tough if you know what you're doing, and I've got it all done. The only question now is this: how do I use the DLC? I downloaded it and added into my game, but when and how does it activate?
Never mind, there was a txt document that explained it.
Welp, I beat the game, and since I am sooooooooooooooooo not going to do the genocide run, like ever, I guess there's nothing left to do but wait for the use of those four crystals in the clear zone. I could try to find the rest of the stuff to make the Encyclopedia 100%, but I don't even know where to start.