Flooded New Londo

Hey guys

So when i walked to the red sealer he said:''I flooded new londo to seal off the 4 kings'' but how can water hold back the abyss?

Since everything that you throw in the abyss disappears instantly,how can water do something about it? And about the 4 kings couldn't they just leave the abyss?

It likely has to do with more detailed magical theory than we learn about in game, due to not wanting to drive away potential players with an overload of information. Water is often highly important in mythology.

For instance, holy water and vampires being unable to cross running water. Water may be an element of cleansing, or it may just not allow evil to pass it.

I'm known for text wall explanations but.....that^

I'll have to use necromancy just once; to point something out.
Oolacile was also flooded! And it also had their own Abyss.