>>531662709
That's how Arona drew sensei previously in a canon segment. It was the first canon depiction of sensei in the game.
Plana also drew sensei looking a bit like anime sensei during valentines when she made cookies that looked like him
The chroma causes whoever it infects to grow larger maybe, but even without the chroma they said his body was covered with bandages and metal plates holding him together even before he died the first time. Chroma makes you look more monstrous, but if you look closely Phrens body is really fucked up under his robes, his robe makes him look imposing when really he's just a corpse under it.
They do imply in the anime that Phren originally looked like anime sensei once
The only thing we know for sure is that he was a somewhat tall man