I cant fully understand what it says, english being my 2nd language doesn't help..
My main language is french - I just headed to french world and see if they said anything in french when clicking the door, though they haven't translated the voices, they're still english.
English is mine, and I can't really understand it >.<
Don't know who it could be. Zaros is a definite-nono, as it goes against all the previous mythology. Sliske is definitely associated with the shadow, but a door in GodWars with all the God symbols on it seems to be overdoing it a bit just to imprison him... Possible though...
Anyways, I wouldn't expect shadow barrage to do anything - this is just a teaser afterall. Also, the screen never shook when I went down to it D=
Random idea....could it be....Jas? Or another elder God?
(Off-topic, do we know if Jas is an elder God or not? I mean, I'm sure he is, but....)
Tbh though, at this point the most plausible person seems Sliske, he's the only one associated with Shadow... Idk o_o
EDIT: To above poster, I think that was probably just a glitch.