Elin Forest is whole Victoria Island?

Don't we not know how far back ellin brings us? It'd have to be over 1000 years back for masteria to be there. Although if we could find out WHY masteria disappeared that'd be awesome. That'll probably be revealed as masteria expands in the present though.

Masteria is pretty much the only place that has a definitely timed past. It's 1,000 years since it sunk but that's all we know. Elin is an indeterminable amount of time in the past, though it's gotta be around the time the black magician ruled Ossyria. We don't know when Sharenian and all that happened so it's hard to say.