The game is not as interested in outside world references as Dark Souls was (Astora, Carim, et. al.). Apart from passing references in item descriptions, nobody ever talks about foreign lands. It's not about one's heritage, after all, but the journey of the Tarnished to the Erdtree. Different worldbuilding.

land of reeds, badlands, Kaiden, The house marais, and the dream world if we count cut content

In Celtic mythology, which had a huge influence on ER, Eochaid is a name of the Dagda, the king of the Tuatha de Danann, or the Celtic pantheon.

There's Eochaid, but idk anything about it beyond the description of the sword:

>Treasured sword of Eochaid, a lesser, long-vanished domain. The copper coloration is not to be confused for rust, but is a conduit for its wielder to move it by their will alone. 
>
>Swords of Eochaid dance through the skies

Of course there's the lands between, the land of reeds, and the badlands are mentioned. Are there any other "lands" mentioned in item descriptions?

How many "lands" do we know of?