I was originally going to do a Fan-Cast for this but i decided just to focus on the one thing that should be introduced in Captain America 3 that if it could work could lead into it's own TV Show/Movie. What i want the most in Captain America is one charcter and his name is the Punisher
I know what you are thinking..why should the Punisher be in Captain America 3. Well the two characters have almost the opposite values and moral centers. Captain America has always had a moral center and will do what he thinks is right even in a world that has a very different moral center than the 1940s. The Punisher on the other hand is the opposite, the Punisher has no moral center..he will kill pretty much any criminal given the chance..Two Characters with completely different morals..that could really work for Captain America 3 and it would be very interesting to see the banter between the two character.I think introducing the Punisher into Captain America 3 could also easily set up the Punisher as it's own TV Series/Movie in the MCU later down the line..
As for who should play the Punisher..well sadly i think they are going to reboot the Punisher. If it was up to me i would pick Manu Bennet. Not only is a good actor see Spartcus and Arrow but he looks the part and could easily be a badass. The only problem is he might be too busy with Arrow but still he would be a great choice..
Also i really do hope Baron Zemo is the main villain in the 3rd Movie with Punisher being more of an anti-hero...