As a part time mage player (Used to be my favourite class until I fell in love with bruisers), I Kindof want to get this off my chest and give my opinion on each rune in socery and see if anyone agrees and potentially start a Civil discussion.
Okay here we go:
Keystones:
Comet: While this rune does have a lot going for it, it can feel pretty meh at some points only really used in lane for some extra poke, but after that, it just kindof becomes non existent to me, Its damage isn't super passed lane and the chance of it hitting with all the chaos occurring in a team fight is low, making it feel kindof awkward to use.
Aery: This one is actually my favourite of the keystones in socery, since it can be used as an aggressive poke tool and a defense tool. Unfortunately I hate to see it being overused by lane bullies, I get that its can be a constant source of extra poke, but it's really intended to be a support rune, it can also feel kindof wired to only get half the use out of it as a lane bully, knowing that there are other runes you could take and get the full effect from it.
Phase rush: And then we come to this rune...oh boy...its fun in some cases I will admit (Kench) but other then being a Niche rune, it has nothing much else going for it, the only champions that I really see use it are Sol and Cass, Sol mainly because he can't until other runes as well and Cass because its extremely easy to proc and she benefits from having such high speed. But other former users like Darius have stopped using it, Darius mainly because the release of conquerer.
Tier 1:
Nullifying orb: This rune, my god this rune, why does it exist? It feels like a rune only assassins would take to increase their hexdrinker prowess, and not much else, whenever I take it, I never really feel it have any effect at all, And In my opinion it should have been taken out for this Nimbus cloak and not ultimate hat.
Manaflow band: This ones a bit of a mixed bag, On release, I despised it, I always wanted to take ultimate hat, but never could since Manaflow was much better and borderline mandatory if you went sorcery primary, but now I don't mind it, It feels nice to have an extra chunk of mana, but not too much, also the region is quiet noticeable and is extremely helpful early on, still feel like it has priority over ultimate hat in most cases though.
Ultimate hat (Rip): Rest in peace my sweet prince, this rune was my favourite in the tree and my second favourite rune overall (First place is overgrowth if anyone cares), it was so much fun to have 60% ultimate cd, and be able to use Kassadin ult every second, it is a delight, and I'm sad to see it go.
Nimbus cloak: I feel like this is going to be a beta Phase rush, only really used on Sol and Cass, maybe champions with gap closer ults could grab it, but other then that, it feels like it won't be very impressive, oh well, we will see.
Tier 2:
Transcendence: Similar to release manaflow, I feel like it takes priority over other runes in this tier, but I Don't despise it as much, since It allows me to build some items I wouldn't If i didn't use this rune (Example, I can get Ludens, Banshees, Archangels and hourglass on MAlz, which normally I would have excess cdr), But I still don't like it as much as some of my favroites because it feels too mandatory.
Celerity (Or as We call it Celery): Like phase rush and nimbus cloak, it feels niche and only taken if the champion has a movement speed up or steroid, the 3% Extra move speed is nice though I guess? I honestly don't have much to say about this rune.
Absolute focus: What, like, who uses this? I totally agree with Op here, unless you're Zed or Talon and feel like you can get super fed and want a little extra 1 shot power, but then again, you still lose it if you take too much damage, and it dosent take much to drop a squishy like Zed or Talon below 70% hp, Also, why take it when you could take the other two and get just as much Ad or Ap from transcendence or more chase power from celery.
Tier 3:
Scorch: I really couldn't care less about this rune, its bland, non interactive and only used to amp early poke, I never use it, even on lane bullies, the only time i do use it is in aram because Gathering storm is shit there and Waterwalking lul.
Waterwalking: That being said, I don't see this rune very often, not that I think its a bad rune, Its just highly outclassed by the other two, why get bonuses only when you're in the river when you can take gathering storm and have more bonuses later on.
Gathering storm: I like this one, but I also like to build for late game, connect the dots and it makes sense why I like this rune.
Final Verdict: Keystones definitely need work, I would say to move aery to inspiration and replace it, Phase rush needs a straight buff to push it towards battlemages, and comet needs a hit to its early, but a buff to its late. Power needs to be shifted around with all the tier runes as the feel like they are mandatory or they feel like you just flat out would never take them, Also please don't remove my precious child (Ultimate hat)
Thats all, I know, an essay, but its no different from the 16 page one I have to write (Funtime.png)
EDIT:
I didn't do enough research in terms of ultimate hat, apparently its not gone, just going to get move to domination, and while I don't agree with that choice, Im just happy its not entirely gone.