-Move the Flame onto Vortex Falls, with an up and down exit leading to the adjacent rooms on the Falls.
-Apply the effect from the waterfall in Toronada that lets you descend, but not ascend, to all up/down exits in Vortex Falls.
-This does not prevent teleports, staffcasting, melding or anything but moving. It just flings you back if you try to go the wrong way.
-Put a valve just above the Flame that allows you to bypass it, but not meld through.
-Make the fleshpot valves into in/out entrances/exits or don't. This does not meaningfully alter the difficulty, for offense or defense either way with this plan.

What if we merge widening and add in the flame to the group, but adjust exits a lil.....

to this:



Even something as simple as the above makes the flame a little more secure. Give it north, west, and south exits and you should be ok. If needed you can add in a second set of rooms in the rest and just make it so they dont all link to eachother, aka, each side might have a south and north exit, but every other room is a west/east exit too. That kind of thing. I do think valves should stay special exits though akin to most every other plane. As a note the above also keeps with the idea of Nil where you can usually break 1 of the rooms, although in the above you can break north and south of the flame, but you also arent retaking the rest of the area.

Although Really, you can usually run to a break point, but on vortex, you cannot run anywhere through windwalls + rainbowclouds. Rainbowclouds kinds of breaks the traditional raid/defense barrier since if I recall, it only hits enemies. So defenders cant move properly but all the raiders can.

EDIT: In the above you can also flop the flame to the other side which makes a realllly long stretch that you can break fairly decently

Is rainbow clouds not limited to only the rooms by the melder?

Malarious's suggestion is a nice start, as the north/south rooms will be breakable and it'll be harder to shut the defenders in entirely. The valves might need addressing still, regardless.

If you are to the west of the flame that means the rooms north and south of you get rainbowclouds. If its the strip with an in/out exit to the flame you have to walk through rainbowclouds, etc. Regardless they can spam travel and get to you causing it all to hit you instantly and you wont be breaking that very well in the least.

@Alianna: Thank you, I do try. Not sure how the valves specifically would help though, they are identical to the whole pillars/pits thing.