BoiGeorge
Based from what I've read the founders didn't have portraits because the moving portaits weren't invented yet in their era. But then again time travel exist in HP universe and the slytherin could have went a bit further in the future and made their own portraits. He seems to be the kind who would do that
It's very funny to read that Merlin was a student of Salazar, and not the other way around. I was just wondering how it would happen, Hogwarts was founded in 990, and King Arthur and therefore Merlin himself lived around the v-VI century, although this is fan fiction, so it's all the author's imagination