Bad Omen from Ominous Bottles in Minecraft can enhance challenges ... with diamond gear and potion effects for all undead mobs, and not just spiders. Ominous Trials already make use of diamond ...
In Minecraft 1.21, that effect will be changing slightly. Now, the Bad Omen effect is obtained by drinking the new Ominous Bottle potion, which comes in 5 variants and can be found in Trial Vaults ...