Complex sentence: Each piece of the castle can be customized for either height, thickness, or both, and most can be further outfitted with defensive features-for walls these are cauldrons of boiling oil, for towers they are arrow slits, and so forth.
Split into simpler sentences: Each piece of the castle can be customized for either height, thickness, or both, and most can be further outfitted with defensive features. For walls, these are cauldrons of boiling oil, for towers they are arrow slits, and so forth.