Spoilers request - hidden maze's wardstone Options

[GotWangi]

Hi all, need a little spoiler with this part of the mod because at this stage I feel like my head is about to explode. So I finally mapped the dungeon (or at least I think so), but just when I thought I'm at the final room, I get a message that I need some sort of ward to access the lower level. There's also another room I believe that gives a slightly different but similar message. Does this mean I'll need two keys ?? Anyway I went back and explore the dungeon again, making sure I check all the pools. 1 hour later and I'm still searching.

So to make long story short, can anyone spoil me on where the required thing is ?