Yes, "a bit of a controller" or I guess you could also say "somewhat a controller" or "kind of a controller," right?
Oxford gives these examples too,
fue medio violento encontrármelo ahí — it was rather awkward meeting him there
me lo dijo medio en broma medio en serio — she said it half joking and half serious
medio como que se molestó cuando se lo dije — she got kind of / sort of annoyed when I told her
https://es.oxforddictionaries.com/tr...-english/medio