Unexpected new planting space in the SW Corner

New planting space though, that's what we're talking about today. I wish I had a before photo, but since I didn't know it was happening until it was happening (and really I was still asleep) there are no "befores"...
There was some strange police activity on our street the night before this all happened. I spent an hour—a very late hour—up watching the action (and I'm still not sure what I saw), once I crawled back into bed I wasn't able to fall right asleep, which meant I slept a little late the next morning. About 10 minutes after I poured my first cup of coffee there was a knock at the door, our neighbor across the back fence was trimming the laurel and wanted to know what I thought about the possible changes.
Let me just say, I don't function until I've had at least the first cup of coffee. It was very kind of her to come over and consult with me, but I felt in a daze. I was not awake. AT ALL. There were lovely draping branches of laurel that sort of fell over the fence and created a green back drop to the area below. I liked them. A lot, now they're gone. I've never seen that meeting of fence styles before, it was always hidden.
But I also knew she really wanted to cut them, they are her shrubs and I needed to just go ahead and rip off the band-aid. Let it go. Not my plants. It's always better to control the green and plant on your own land rather than rely on the neighbor's plants—and so now this is my view.
We'll make our way over there eventually, to look at it in detail, so you can see the new space. But first I want explain what's going on in this area, which you may have noticed in the first few photos. Last summer my Sasa palmata 'Nebulosa' (wide-leaf bamboo), in the stock tank, suffered a mite infestation. I cut it all down to try and stop the mites from infecting the other bamboo.
I was good timing as the ice storm we had in February would have flattened that bamboo anyway. I just got ahead of the game. New shoots are doing their thing and it's filling in nicely.
Behind the bamboo tank there are a few mahonia and aucuba finally starting to fill in.
And a vine climbing the fence, Holboellia angustifolia var. angustifolia.
Mahonia x media 'Marvel' from the Sunset Western Garden Collection. You might remember I just picked up one of these when I spotted it at Pomarius Nursery a couple weeks back. Little did I know I was going to have an empty corner to plant in!
So, there it is. The empty corner.
Here's my quick sketch to try and help you understand why this used to not be at all visible. The neighbor's laurel just draped over the fence and provided a green screen to an area that—I'll admit—was kind of a dump for heavy, wet, rain gutter cleanings and never really got cleaned out back when we put those stock tanks in; after building the patio and before installing the shade pavilion. 
In other words... untouched for YEARS.
And now there it is, a scar for all to see.
And it's not small...
If you're wondering why we placed those tanks so far out from the corner to begin with, well, so am I. I think perhaps back then I never dreamed I'd run out of garden space. 

The poor variegated fatsia took a beating in the February ice storm, new growth has begun to pop out of the lower trunk, it will be interesting to see what it does now with more light.
This corner—the SW corner—was my last really dark spot...
...after the big reveal last September of the previously shady area behind our garage (the SE corner), which I wrote about here. A large potted daphniphyllum is helping me to feel better about that spot (please pardon the galvanized tubes/pedestals that have not had their planted tops/trashcan lids put in place yet)...
I thought I should dig up a couple of old images to at least give you an idea how dark the newly revealed SW corner used to be. This is August of 2019. You're looking at the space to the right of the shade pavilion, that just sort of fades out of sight...
And here's the view in September of 2020...
And now...
So, I've got some scheming and shopping to do!
From the patio it's not terribly obvious, unless you know to look for it.
But it's there, and empty. I don't do empty. Any suggestions? It's a partially shady area. I'm considering a tree, or maybe another stock tank...