The story may not be everyone's cup of tea, and I get that, but to say its dull is just crazy. Yes its full of grim sorrow, but the emotion is heavy and real. The voice acting is phenomenal and the music is as beautiful as the visuals. Even the side quests and minor quests have depth for story to the point I forget its not the main story. Some of the missions manage to be action packed while being a cinematic show piece A Message in Fire and Ghost in the Smoke probably my favorite missions so far. Both drastically different from each other.
The combat hasn't gotten stale to me. Once you take the first castle. The enemies are stronger and fight differently. They do have more HP but its quickly negated once you get certain armor and upgrade your katana more. The enemies from the first section of the island stay the same and you'll see them around, they die even faster when you're stronger. They also throw in a new faction of enemies that fight much more skillfully.
But yeah, fuck spear guys. I've unlocked Heavenly Strike and Dance of Wrath. I spam it on those guys now because the newer ones have excellent guard, and stagger ability. To give you an idea how tough they are. Later you get a weapon with a certain ability to make enemies turn on each other temporarily. I've used it on several types but the spear guys are the best choice. I watched as one spear guy took out 2 brutes, a shield guy, and an archer before he was taken down by another spear guy. They are also the only ones I've observed take down bears and not get ragdolled everywhere until they die.