I think you might be referring to "Fate/Zero" season 2, but there is actually only one season of the anime series Fate/Zero that was released in 2011-2012. There isn't an "ED2" (second ending theme) for Fate/Zero either.

Fate/Zero is a prequel to the Fate/stay night visual novel and anime series. It covers the Fourth Holy Grail War in the Fate series' fictional universe. The first and only season of Fate/Zero consists of 24 episodes.

If you're looking for additional content related to Fate/Zero or the broader Fate series, there are:

1. Light novels by Gen Urobuchi

2. Manga adaptations

3. Video games

4. Other anime series like Fate/stay night [Unlimited Blade Works] and Fate/stay night [Heaven's Feel]

Is there something specific about Fate/Zero you were interested in? I'd be happy to provide more information if you can clarify your question.