Yeah, it's definitely one of those things where one, you need to know when it's coming and two, exactly how to fight it and deal with it from reading up on guides and such online, but that's definitely not something you're going to discover by accident or on your first run through. The amount of damage that thing can do is IMMENSE. It will level your entire base and kill everyone in your party multiple times if you haven't done exactly what the guides and walkthroughs tell you to do (and I imagine these were prepared by people who also didn't get it the first try and had to experiment and do trial and error to figure this stuff out).

I dunno, some people enjoy that kind of abrupt challenge, but I'd prefer to ease into things like that, especially if the cost for failing or screwing up is very dire and means having to start completely over again (which sucks more depending on how long and how much effort went into getting to that point in the game). Otherwise, it kind of says "ha ha, all your efforts are worthless, scrub! Git gud!" and I'd be like "yeah, cool story, bro, looks like I'll be playing something else from now on and you can forget about me ever buying any DLC or sequels you create. Cheers!" In a world where we have tens of thousands of games to play and choose from, it's best to be kind to your player base.

On that note, I haven't ever played Dark Souls or its sequels, but let's just say I've heard and have seen plenty to keep my distance from that franchise. :P