It didn’t really break it, just made it more difficult. As far as I see, the addition was, that everytime an egg bomb hits a party member, because he failed to dodge them, spiders (including a veteran) spawn on top of that player. If your entire party fails to dodge the bombs, you’re screwed and will have to reset. So yeah, the key to defeating the Nightmare Tree on the f/u path, is to attack from range with non-AoE attacks and to dodge the bombs. I agree though, that this is a pretty boring fight and can be frustrating at times.