Cameron Monaghan
When I saw he was going to be one of the stars of this I knew I should plan on watching this when it airs.
He is a phenomenal actor. Brilliant and talented. He really sinks his acting chops (very strong chops by the way) into everything he's in. He takes acting parts very seriously. He does his own research for parts so he can really get into the character and get it right. For example, he stars on a show called "Shameless" and his character became bipolar so he watched documentaries and interviews and read psychological journals on bipolar so he got it absolutely right. His "Mercy Street" character has PTSD. So I suspect he went through a similar process to get ready for this. Also, he has a lot of natural and effortless talent when it comes to speaking lines and the physical parts of acting as well, facial expressions, body language, movement...etc.
He will be a big highlight of this miniseries for sure.
Also I can't wait to see more of him as The Joker when Gotham comes back this fall.