Super_Boom on 14 February 2017
Late response to the question...but for me, it's usually a combination of character development and character depth. Even if development is standard for the medium, I just love seeing characters that grow with the story. It makes them feel much more alive. I'd even go so far as to say dynamic characters is why I enjoy this medium as much as I do.
That being said, I've begun to appreciate villains for the opposite reason. The less I can empathize with a villain, the more terrifying I find them, and makes them much more effective. To me...the best villain is someone I "love to hate"...and sometimes needless sob stories dilute that feeling.
NNID: Zephyr25 / PSN: Zephyr--25 / Switch: SW-4450-3680-7334
