I have read a list of all the weapons in the game, but still can't find alot of them. The light sword, for example.
Can anyone please post a list of artifacts and where to find them?

Here's one but it don't tell the location.

Light sword can be found on a chest ( inside one of the huts )in bayjin OR from the buchaneer ghosts besides the sunken ship.

There are a number of items that are not found on a regular base. Light sword, for example, is extremely rare; i didn't find it yet in 15+ games. It might be (very very small chance) in a specific chest or monster drop. Others are slightly more common; for example, one chest may contain excalibur, or one of some other good items (for example, a great regeneration item), or nothing interesting at all. And others, like marumase blade, are quite common, and appear in about every second game.

There are others that are only generated as random drops from high level monsters. For example, i recently found the Blades of Aesir (?) for the first time (best axe i found so far).

Like Wereboar, I also have played a large number of games and never got the light sword. I did get the light shield once, it was well worth the wait! Only got muramasa blade and excaliber twice in about 10 games.