Fate/Zero's second season starts off in episode 14, straight off with action in the battle between Caster and Saber/Rider/Lancer and also the battle between Gilgamesh and Berserker. This sets the tone for the whole second season, giving it an even darker and more focused tone.
Story: The story from here continues on as smoothly as the first season's story did. It picks up right where the first season left off, and keeps moving forward with as much momentum. I thought the flashback episodes of Kiritsugu's past gave for a very interesting subplot and gave better development for our favorite morally grey protagonist. I can talk about the ending in two ways. If you have already seen Fate/stay night, then the ending gives the full explanation for the events leading up to Fate/stay night. If you haven't seen it, then you might think this ending a little anticlimactic. It's your choice as to watch this or Fate/stay night first, but I'd say watch this first.
Art: UFOtable does what UFOtable does... This is one of the best looking animes of all time. It has amazing character designs, being rather orthodox with small flares hearkening back to the servant's historical stories. The color pallet is very nice, with many dark colors outlining the backgrounds and lots of bright colors in the foreground and battle scenes especially.
Sound: The music, composed by Yuki Kajiura, is absolutely brilliant. This is one of her best works, complementing the great voice acting in the English dub and the original alike.
Characters: The characters in this get much more development, as characters dying off calls for a more focused development of our main characters. The 180 that Kirei pulls and the back story of Kiritsugu are both great, and the development of Rider & Waver's friendship, coupled with the woes of Kariya Matou, made for some very memorable characters.
Enjoyment: The second season is much more focused and fast paced than the first, providing for a much more enjoyable experience overall. The action mixed with the character developments/interactions are definitely worth watching the show for, being complemented by the outstanding music and animation.
Overall (Both Seasons): Fate/Zero is an example of slow and steady winning the race. The first few episodes, while excruciatingly boring, provide for a great introduction into the world that is Fate. Although being very slow for the first half, it lays the foundation for the masterpiece that the second half made this show into. The only downsides of this show are the ending and the beginning, the beginning being rather slow, the ending being rather anticlimactic.
