Some minibosses seem a little easy

[Fluffiest Princess]

Really enjoying the game, but the difficulty between minibosses seems to be all over the place. In particular:

Phaztu Othaloth, the Aberration miniboss in the Eschaton city. He's actually quite tricky when you don't have the air dash. Once I had that ability, though, he was absolute cake. Dodge through his projectiles, beat him up for a bit, take damage, then go and chill in the middle of the room occasionally dodging attacks until my shield fully recharges. No matter how damaged he got, his attack pattern never became any more threatening, and the waves of projectiles were only hard to dodge when I was trying to get close to him.
My suggestion: Ideally, he'd have another attack to keep the pressure on and force the player to keep moving, but it might be better to let him summon Screamers or Crawlers when his health gets low. I'm oddly fond of this guy, just because he has such a cool name and some of the best battle music in the game, so I'd like him to be more challenging.

The twin screamer bosses (can't remember their names, sorry) do a bit better, with one of them using a massive wave of fireballs when the first one dies - but that's just a one-off, as far as I can tell. It's still very easy to run up, hit them, then retreat and chill out until your shield recharges.
My suggestion: I'd have preferred it if the second boss had kept using the massive-flame-wave ability. Also I'd have preferred if there were more environmental hazards in the room, and/or if the bosses did a slightly better job of retreating when attacked - it's a bit too easy to get close to them and stay there. Adds would probably make this fight too hard, given how restricted the space is.

The Quietus Ternion, the three Noctoctus bosses in the Valkyrie base. This was a really challenging, interesting fight for a while, with the pressure of needing to constantly keep moving and not get trapped and pummelled in the lower section between the three bosses. But once I killed the first one, the fight might as well have been over! That gave me a safe place where I could wait until my shield regenerated, then go back in, hit the boss a few times, and retreat before they got through to the soft squishy centre of my health bar.
My suggestion: I think the best option would be to enable them to teleport once the first one has been killed. Failing that, you could give them a combined health bar. They're never going to be super-difficult, but they ARE a first zone boss.

The Herald of Ruin, the Sentinel miniboss in the Cathedral. While I think the boss design is very interesting, its projectiles seem to be really weak considering it's a fairly late-game foe. Its massive shotgun attack is incredibly damaging, but since there's nothing around other than the boss, and the Herald's attack pattern is entirely predictable, you should only ever get hit by it once. The fight isn't lacking in fun, and it's a nice change from the rest of the zone, but it's kinda easy.
My suggestion: Ideally, he'd have a third attack - a ground-covering wave of some kind, forcing the player to actually use those grapple points above the arena. But I realize that would be a lot of extra work since nothing else uses an attack like that! If the Herald could fire those arcing projectiles more often, so there were still some on-screen when it used the shotgun, there might actually be a bit of a threat here. Alternatively, he could spawn a few adds - even Aranaea would make the fight more of a challenge by distracting you from his shotgun.

Conversely, Luther (the meteoroid) and Cnidaria (the medusozoa) do a great job of getting more threatening as the fight goes on. Cnidaria is kind of a gear-check as much as she is a skill challenge, but I think she's fine. The fight is a lot of fun. Luther is great - possibly the best miniboss in the game in terms of the challenge being spot-on and getting harder over the course of the fight.

Arlie Waylon (the panzer) and Llaeyea Yi-bot (the cultist) stay at the same threat level throughout, but the steady supply of monsters keeps the fights interesting, and I liked how Llaeyea's main threat was the swarm of Crawlers that bother you while you're trying to kill her. She wasn't really much more than a regular Cultist with a lot of health, but between the constant swarm of adds and a decent variety of attacks, it was still a fun fight!

Arlie is a little one-dimensional, since he only really has one attack, but the only change I'd want to make is to add Hunters to the spawn pool for that area - having to dodge railgun shots while fighting Arlie, or trying to track down and kill Hunters while remembering to dodge his attacks, would be a nice challenge.

Hiram Macias is... I hesitate to say 'fine', because he's extremely frustrating if you don't have the right upgrades, but I don't think he needs changing. I was, eventually, able to beat him with no corrupted upgrades and with Nemesis active. The difficulty of this fight is the risk of falling off the bottom of the map, and it varies hugely depending on whether the player is on the Resist or Embrace paths. If anything, I'd make the first part of the fight a bit easier by reducing the number of clones he spawns, and have it build up gradually over the course of the fight.

I'm a little sad there isn't a miniboss Devourer, because those things look so cool. There's no Wurm miniboss either, but I hate wurms so I'm not about to complain.

(Oh, this is my first playthrough of the game. I'm on Hard difficulty. Most of the minibosses took me two attempts to beat, although Cnidaria took three because I fell off the platform, Arlie and Llaeyea took me several tries, and Hiram took me... more attempts than I'd like to admit. I think the Ternion are the only miniboss I got down on my very first try. I'm guessing the fight mechanics don't change on Insane, and it's just that the damage and health numbers are bigger. And please - while this is criticism, I only critique because I really enjoy the game!)

[ClockworkXI]

Thanks for the feedback! We tried various things with the minibosses, but I do like those that get harder as the fight goes on the most. As you noticed, some of them have wildly different difficulties depending on your abilities/perks. Some of them are harder just by the fact that they are so far away from the sanctuary. The meteoroid mini-boss is my favorite one, but I do have a soft spot for Arlie as he was absurdly hard during development (we initially wanted him to almost impossible when you first met him, having to come back later).

[Fluffiest Princess]

If the DLC is still being worked on, is there any chance of a small tweak or two to the minibosses? I think only the Ternion and Phaztu really need it. Phaztu only needs some monster spawns rather than any new mechanics. The Ternion need something to keep the fight interesting once one of them is down. The Herald of Ruin is easy but not in a boring way, and the others are all fine.

[ClockworkXI]

We are pretty much content locked at this point, but I'll bring the idea to the rest of the team.

[Fluffiest Princess]

Thank you! I really appreciate it, some more variety in the challenge of the minibosses will make my second playthrough a whole lot more fun.

(The main bosses are pretty much spot-on, though. Dominion is particularly brilliant.)