Needless to say in maelstrom arena, my personal opinion is that Vault of Umbrage is the most RNGtastic and infuriating stage, the rounds themselves are fine, the boss fight is interesting, but when you get continually out RNG'd by the Plant Spores and stuns that seem to appear out of nowhere, especially during the Minder Phase, I have few complaints about Maelstrom arena, but this mechanic of Plant spores spawning within the Minder's circle and afflicting you is just ridiculous, I've already completed the boss fight multiple times, and now it just seems like luck of the draw at this point. Whether if this was intended I don't know, but if it was, then it is a very big flaw which makes the whole fight repetitive and annoying.
I perfectly understand the designing of all of maelstrom arena, and I enjoy most aspects of, despite only recently completing it a couple times, the environments are great, boss mechanics are fun (and avoidable), and often the only times you die are due to your own mistakes, leaving room for huge improvement on your knowledge or even approach to said mechanic. But the Plant RNG god is an affront to what Maelstrom arena is, as it is completely out of your control, which isn't fun or even preventable to a certain degree.
There is merely one addition that you need to make this problem disappear, is that you can apply a buff to the Minder's shielding AoE, perhaps reducing the damage taken from Volatile Poison by 25%, 50%, or maybe 100%, something to allow you to stay within the circle so you don't melt in the circle and outside of the circle. Therefore, if the damage was there, it would be more of a threat outside of the phase and you could have the ability to deal with it accordingly.
Though I have merely a few complains about Maelstrom Arena, this is one of the biggies, as it is a large roadblock of artificial difficulty that is needless and incredibly frustrating, the other complaint being the cost of armor repairs and soul gem usage, but those are only minor complaints.
I thank you for reading this, and if you have any suggestions/feedback then please do confront me with this, as I see nothing more than an oversight of design.
On me mum's guar! N'wah n'wah!