ja' muHwI':
>I tried to find an expression for "Really?" like in: "...wow...really???"
What are those multiple question marks intended to imply?
Disbelief? Consider {nuqjatlh?}
Surprise? Consider {chay'?}
Relieved confirmation? Consider {toH!}
Without more context, I don't know what the "best" expression would be.
-- ghunchu'wI'