Apologies in advance for rambling. Tl;dr I enjoy the Kyrian playstyle, even if you can prove to me that the damage it does is worse than all the other options.
I’ve been a Kyrian arcane mage since the beginning. Before it was meta. Before any streamers or “gaming elites” decided it was the way to go. I liked the allure of a 30 second cooldown and I honestly liked the Bastion transmogs the most. I spent one day as Venthyr and that was this patch (because those treasure chests in ZM that were 2 feet above my head but unreachable were agitating me). I can’t speak for how other covenants / specs will play, but maybe I can give some insight into why I legitimately enjoy the playstyle, and why it’s not for everyone. I do more raiding (currently progressing heroic) than I do M+ (I have done +15s on everything I think and my group will probably look to start pushing soon), so consider my opinions compared to my current content.
Arcane has suffered from a major problem for a very long time. It’s a high risk playstyle that doesn’t often retain the high reward expected from from taking risks. In BfA, if I executed everything absolutely perfectly on a fight, I was still going to do less damage than I would if I was playing frost unoptimized and just messing around. In Shadowlands, it feels a bit more competitive to play arcane, however as mentioned above, there’s still a lot of risk involved.
The playstyle for arcane, Kyrian or not, involves a fairly heavy amount of management. It’s not quite as simple as “click the button that glows” because you need to keep track of mana, charges, cooldowns, and movement (I know arcane is not unique in this concept). At the end of the day, it’s a style where you actually have a lot of control over what happens and when, if you can focus enough to manage them all. That’s why I like the playstyle - I’m a control freak, and I like being able to decide when my damage happens vs. getting a proc vs. just casting the same rotation over and over on every fight. The only things I don’t have control over in the way that I play (which is likely sub-optimal) are 1) if arcane barrage crits and 2) if the mobs were close enough for barrage to hit all of them.
Kyrian adds another layer to that level of management (I’m assuming you pick the Harmony legendary to go with it). Most people don’t want more things to manage in a fight, and I’ll be honest, it often overwhelms me despite having played mage for 15 years and arcane for probably 10 of those years. However, this playstyle has addressed 2 issues that I’ve had with arcane - one longstanding, and one new.
The longstanding issue is that I’ve never liked arcane barrage. It typically signals the end of our burst phase but usually doesn’t hit nearly as hard as a “combo-spender” should hit. The Kyrian-Harmony build changes that, especially now with the unity legendary. Arcane barrage hits like a truck that’s being hit by several other trucks now. Maybe I’m a bit simple-minded about it, but being able to crit something for ~200k and have your group say “where’d that mob go?” is really satisfying.
The second issue is that I really don’t like Touch of the Magi and I’m tired of blizzard trying to make it a thing. I much preferred Charged Up over this. I know it deals a ton of damage and adds more things that I can control, but I feel like it has inadvertently created a detriment to the spec as a whole. I chose to go with radiant spark because I felt it would lessen my reliance on Touch as a mini-burst (which it has).
I haven’t seen it for a while, but for a good chunk of this expansion, arcane mages were complaining that we weren’t getting enough procs of Clearcasting to store and use during Touch to optimize damage. It’s a flaw in the rotation that I don’t need to care as much about with Kyrian. As Kyrian, even with the 2-set, I don’t enjoy casting Touch. It’s just another extra buff with another extra cast that’s getting in the way of damage. Am I missing some damage from not optimizing this spell? Yes. Do I still enjoy the style? Absolutely. If I was offered a talent that would change Touch to something else, I would take that talent. I almost don’t even care what it is, I just dislike the spell.
When it comes to M+ specifically, I had resigned myself early on to the idea that I’m not going to be the most useful member of our runs since I’m mostly single target. With the inclusion of Unity, the game has completely changed. I may not be able to beat others in large pulls, but the damage increase is noticeable. It creates a very… strange… aoe rotation, but it feels so much better than it did to me. I’m not capable of putting out the same amount of damage as our MM Hunter with his Wild Spirits, but being able to focus down the priority add while also now cleaving feels really good.
At the end of the day, the arcane spec as a whole is suffering the way that lots of other classes are. The specs and playstyles are half-baked, and it’s only the current iteration of borrowed power that makes them work. For me, Kyrian is what makes the playstyle something I enjoy playing, even if the numbers aren’t always up-to-snuff. Others don’t enjoy the playstyle for Kyrian and, even though I think it’s super fun, I totally understand people’s disdain for its style.
In BfA, arcane felt like it was in the middle of being reworked and the team just stopped. The spec felt incomplete and like something was missing. Shadowlands feels like an attempt to throw some random ideas at it to see what sticks and what can complete the build for a more permanent solution. The problem that it created is that within the arcane community, which is remarkably small, we now have 2 factions: Those who like the Kyrian style and those who don’t (regardless of which does more damage). Numbers can be tweaked. Spells can be balanced. But playstyles and rotations require a lot more work to nail down and my only real hope is that we don’t go back to being as useless as we were in BfA when the next expansion hits.