League of Legends update 25.S1.4 (15.4) preview was posted by the developers. Almost 20 champions were changed, including Mel Medarda, Kog'Maw, Twitch, Ekko, and Ashe. The list was revealed by Matt "Phroxzon" Leung-Harrison on X.
Atakhan commentary
This patch, we're making some changes to impact the rate at which Voracious and Ruinous Atakhan spawn in games.
Our intention is to make some tuning changes that make Ruinous Atakhan more likely to show up in Pro games without changing the rate at which he shows up in regular games much (which is about ~15% of the time in slow games).
We hope to get this balance in a good spot by the time First Stand comes around.
Champion rebalance commentary
Mel
Mel's winrate for this patch is being tanked by her W, which is erroneously suggested to be maxed 2nd (which we're fixing for this patch). She's getting a significant influx of new players, which is tanking her winrate somewhat, but she's still very popular which is great. Changes in this patch are targeting opening up moments of vulnerability, through early E duration, lowering her effective range and W duration. This should require her to get in range more, stay in range to build up R stacks and be more vulnerable when doing so.
We intend her to be weak into beefy frontlines that she has to stack up and a bit more friendly/enemy comp dependent (setup for E, needs a good reflect to scale well). In solo Q, she's intended to be a lot more effective and she is intended to start to fall off around 3 items-ish, but have a pretty comfortable ramp up until then (this may need to change at some point in the future though).
Ashe
Ashe took a pretty significant hit from the changes on 15.1, so we're looking to pull that back a bit.
Kalista
Has been an extremely high presence, even in fearless world, so we're pulling the changes back there a bit.
Warwick
Warwick top has emerged as a pretty strong pick over a pretty extended period of time, so we're looking to take him down a tad there with a top skewed nerf.
Patch 25.S1.4 will go live on February 20 (on Thursday instead of Wednesday). The changes have already been tested on PBE servers. Mel Medarda and Atakhan remain the primary focus of the developers since their addition to the game this season.