On April 5, the developers of League of Legends released an unscheduled micropatch that nerfed the champion Yorick. According to the developers, his effectiveness in battles was above the norm. This was announced on the official LoL developers' page on X.

Full List of Changes

 Shepherd of Souls:

• Fixed a bug where Mist Walkers did not deal 60% damage to monsters when leaping.
• Damage taken from minions and monsters: 40% → 60%

Mourning Mist:

• Slow: 30% for 2 seconds → 30% for 1.5 seconds
• Movement speed increase: 30% for 4 seconds → 18/21/24/27/30% for 4 seconds
• Armor reduction: 18/21/24/27/30% → 13/16/19/22/25%

 Maiden of the Mist:

• Damage cap on monsters: 50 → 30

Previously, Riot had already nerfed this champion. More details on the previous changes to Yorick can be found at this link.