Calvin Vail a.k.a. Leafyishere is the protagonist of the Half-Life series. He is a theoretical physicist who is forced to defend himself and the Human race against hostile Aliens and other enemies following an experiment gone wrong. In the process, he becomes an almost legendary resistance hero, eventually becoming one of the leaders of an uprising against the alien invaders. (And literally a famous YouTube cyberbully. he is also literally enemies with a certain gnome. he literally makes commentary videos literally roasting people on the internet, literally.)