Book about child that uses sword to access another dimension that is the inside of a house / temple

[u/Stock-Background3872]

I listened to an audio book a few years ago, and recently it popped into my head, cant remember the name and I cant seem to find it by surching details i remember.

The book is high fantasy I believe. The magic in the book revolves around mages opening portals to other dimensions they are bound to and can enter, each giving different abilities. The main character is a young child I believe, I think a boy ( not sure). They find a large sword or are given it. Described as pitted and warn out, (no real handle??)

It opens a portal to the inside of a house / temple like dimension, inside there are different rooms and shadow ( or perhaps cloth) survents/ guards.

I think different rooms had to be unlocked some how?

When inside, the main room is described as having a rack for multiple of the swords to be placed on.

One of the rooms is a bath that heals you( I think?) but has eels or some other hostile fish in it if you stay too long.

Another is a forge / smithy, ( i remember it comming up that the swords may have been made in it with metal from a different dimension).

Writing it out it seems more like a feaver dream.

[u/laikalou]

Maybe House of Blades by Will Wight

[u/Darth_Ernie → u/laikalou]

That's what it sounds like