Congratulations, you are now playing one of the best games ever made. Four hours in is nothing - the game takes 60+ hours, has tons and tons of sidequests and extra's, and it just gets better and better as you progress.
About the Abyssion sword - I take it the guy means something else (he got the name wrong), but revealing that would be a spoiler. Let me just say that it's the game's main sidequest and has a high risk/high reward.
I drink your milkshake.