Patch 25.14 overview
Champions you recently played
No change
Other Champions
Our star dragon is building a bit too tanky and getting a bit too much damage for free when he does. We're hoping to shift some of his power back into building damage, while not totally gutting his ability to adapt to a more durable build.
Base health increased. W damage increased.
Bel'Veth has some extreme extremes when it comes to attacking quickly, we want her to still maintain some of this while bringing it down slightly. Our hope with this is that Bel'Veth can remain strong when her ultimate is active, while also being a bit more restrained when it's not. Previously, we tried her "start with Ultimate" active, but we lost the excitement that comes with her ultimate and removed too much of its identity, and came with too much reliable power if she made it past the mid game.
Base armor decreased.
R cleanse change. Q bugfix.
Q heal increased.
R healing per second increased. Visual bug fixes.
W cooldown reduced at higher ranks. E AP scaling increased.
After the changes made to crit a few patches ago, Garen has been feeling a little less "DEMACIA!!!!" and a bit more "De... man see how little I can do.". So we're reverting his Arena-specific changes to help him fight back in the Noxian Arena.
All abilities adjusted.
Base AD decreased.
Lux is a dominant champion and a bit too unassailable with her long-range onslaught of spells and CC. We've previously made some changes in Arena to help her out, and we're looking to pull some of that back.
The dog's nose is feeling a bit dry, and Naafiri could use a bit more bite to go with her bark. We're looking to increase her abilities as an assassin as well as help her bring her pack back together if they fall due to some AoE or poke.
Passive AD ratio decreased late.
Ryze is still sitting as one of the top mages, and isn't reliant on augments. These changes hope to hit some of his utility and damage without gutting his identity as Mr. Mana.
Armor growth decreased.
In Arena's past, Shyvana was a force to reckon with. However, as players have gotten better at the mode these changes have had a bit too large of an impact, so we're reverting her Arena-specific adjustments.
Taric isn't looking as fabulous as one would expect in a 2v2 mode. While we are aware that small changes can have a massive impact on Taric's power level, we think we can cautiously walk back some of his Arena-specific changes.
Q damage decreased.
Shotgun knees are too cool to keep down. We're reverting some of the Arena-specific nerfs and giving him a touch more umph to pair with it.
AD growth decreased.
R heal per hit increased.
Q damage increased late. E damage increased late. R damage adjusted.
Q and W damage decreased.
Items you recently played
No change
Other items

Blade of the Ruined King
Blade of the Ruined King has fallen out of favor recently. Meanwhile, there has been both a rise in popularity of health stacking within the game, which means BoRK should be a more popular pick up. To help it get back on everyone's radar we're buffing the % health damage this item provides which is the item's biggest selling point and fantasy.

Haunting Guise
Haunting Guise stacking goes against what we typically want out of our item system, namely that builds should have peaks and valleys where there's room to beat someone on a weaker spike. As this item's passive stacks (and it's intended for the upgraded versions to do so), we're locking players out from building more than one at a time, as the amount of early health that Haunting Guise stacking provides ends up making champions unassailable.

Kraken Slayer
Kraken Slayer is an overall weak item right now, both for melee and ranged users. As such, we're looking to buff it equally by making it a faster early spike and playing up its unique difference with Blade of the Ruined King, namely making it deliver more damage to low-health enemies.

Phantom Dancer
Phantom Dancer is the least-purchased attack speed-crit item in the game so we'd like to buff it enough to feel more competitive. As it doesn't have any really unique outputs, we're going for a sharp price decrease that should help it feel like a very quick spike for crit auto-attackers.

Rod of Ages
Now that the Rod of Ages craze has passed (what a great time it was), it's time for us to re-investigate how this item is performing. Ultimately, we'd like it if it was clearly good for the really mana-hungry champions out there who need to stack as many resources as possible. As such, we're playing up its scaling and mana-stacking power to make it great on that unique set of champions.

Serylda's Grudge
As tanks have moved into viability AD assassins have started to struggle a bit too much in Arena. This should help give assassins better tools when durability gets too high.
Runes you recently played
No change
Other runes

Guardian
Guardian only has a few core users right now, but it's meant to be a reasonable consideration for enchanters who want to index more toward helping out their teammates. As such, we're buffing up the level-up value and AP ratio while reducing the bonus HP ratio to keep it consistent on its most common tank users while making it stronger for those who don't buy as much health.

Unsealed Spellbook (Smite)
We're happy that Unsealed Spellbook is back as a high skill Keystone option for players who can manage the extra mental load of picking the best summoner for each situation. That said, we're not happy with how much it skews contests over epic monsters. While taking Smite is fine, the fact that its damage progression often outpaces junglers is not. This change ultimately results in Spellbook Smite being clearly weaker than junglers' Smites at almost all points in time.