Clearly the easiest way to test if Avery could demolish water was to attempt it.

Unable to demolish. Mana return greater than configured.

New error message. Interesting. At the very least it was more information to use in the future. Greater than configured implied there was a hard limit to how much mana she could gain at one time. The obvious answer would be that would be her maximum mana, or perhaps the available space for unused mana. That would incentivize a dungeon to use it’s mana as it received it, so as to take advantage of the boosts from secrets being discovered and things being killed; having a full tank would result in losing those sources.

If she couldn't simply demolish the water as a singular object, maybe the answer was to cordon off sections of the area and then eliminate what was contained within the room. Fortunately, the mana return from the slimes hasn't completely petered out yet; while lesser greens were down to two mana per death, each of the variant species had its own rate of mana return depreciation, and any of those types would be immediately shredded when put in the path of the annihilation that was a greater blue slime. On the less fortunate side, they were still providing what the lesser greens had as a base; twenty-five mana before reductions.

As she hadn’t thought of it while yelling at her invader, Avery still wasn’t able to clean up all the slime goo slowly filling her corridors for the remaining bits of mana locked within their less-than-living forms. To think about it positively, that was another source of mana she would be able to tap into beyond what was acting as an influx from deaths. With that in mind, she was more than reasonably able to spend some points trying to figure out this water situation.

The first step was to attempt building a door under the water in order to cut off one ‘part’ of the liquid from the main body.

Unable to construct. Space currently inhabited.

An unfortunate, but reasonable, error message. No building doors in solid stone blocks, had to clear out the stone first. Speaking of which… Hopefully it would be enough to construct a doorway in the time between demolishing a cube of water with the manual option and the liquid collapsing back in on itself. Queuing up a basic stone door, she mentally prepares herself to spend the ten mana and-

-CRACK-

The sides of the tunnel where Avery had demolished the water suddenly split, and the level of the water above dropped the exact amount of the demolished liquid. Shooing away the error message about the construction, the mage examines the location to see what happened.

First of all, the water was apparently completely unaffected as a whole, other than being slightly lower. In a ring around where she had taken out a segment of the liquid, the stone had fractured cleanly around the demolished cuboid. From what she could tell, it was angled such as that the top of the crack was slightly closer to the downward section of the tunnel than the bottom, though the average location was about a third of the width of the removed section closer to down than up. Not that she could do anything with it at this moment, but it seemed like that could be a part of a puzzle of some sort later. A code having to do with the frequency of the rings, which would then be input into a chest maybe. That would be better than the stupid pre-generated puzzle box she was currently stuck in.

The ritual required line of effect between the gem and her body, so as of now, Avery was in fact trapped in this chest. In a minute she would have to remember to get properly angry about that.

If the easy solution wasn’t going to work, Avery was just going to have to get creative. If a door is open, the oncoming rush of water wouldn’t be able to knock it down. If she closed an existing door, it would push the water out of the way rather than throw up an error message. If the water trapped behind a door wasn’t connected to the rest of the water, she could safely deconstruct it.

From a safely dry portion of the third floor, Avery starts building herself a downward shaft. This would be something she was going to do at some point anyhow, so at least the mana wasn’t going to be wasted. Unfortunately, for what she intended spiralling the hallways to make them count as separate mana generating units wasn’t going to work. This was going to be a long mana-sink that only gave her one mana regeneration. At least that made it more efficient in terms of mana spent per meter of depth. While spiraling downward Avery had a limited grade from which to work with; on average she could only get three meters or so per ten mana spent. With no limitations on the hallways being usable by creatures with legs, she was getting a full meter per mana.

So much better than trying to use the demolish tool manually.

After a little bit of micromanaging the Blue, Avery had enough to offset the investment into her transit tube. Just to make sure, she brings it down another ten meters. That could be a secret, holding some sort of treasure underneath for anyone who checks back under the platform after it’s sent back up to the top. Thinking forward a bit more, she installs doors at the top and bottom of the downward tunnel. One would be the floor relative to the outward tunnel to what Avery was tentatively going to call the fourth floor, and the second lower one would be a closable surface in the event that she needed to go even deeper, but still wanted to have a chest to find in the wall. Alternatively, she might be able to bring water up through this passage to… do something. It was a work in progress.

With one more hallway facing toward the water source, Avery makes a door set against the side of the tunnel. The next hallway would breach the cavern and fill the structure with liquid. Hoping she was right, the necromancer opens all three of the doors. Each of the slide into the wall adjacent to them, leaving a path for the onrushing tide to flow into. Once said onrushing tide was broken, she would be able to work on whether or not her plan was even feasible. A flick of mana, and the corridor connects with the cavern. Again the water level up above drops as the liquid rushes to fill the newly available space. Rapidly equalizing at the same height as in the fourth floor’s drop, and presumably inside the cavern as well, the water slows its rise to a crawl. Now or never.

Closing the doors… Worked. Perfection. That meant that entire thing would work. In the shaft, the water level stops rising, and outside the shaft it increases back to the previous rate of change. Now to demolish this one room worth of water. Ten meters below the surface, two meters wide, and cuboid. Total of forty cubic meters of liquid. And…

Demolishing water will generate 1040 mana, continue?

Yes

No

You have gained 1040 mana.

…

Unlimited power.