Crown of Lucion is a Seasonal Unique Helm. It can be used by any class.
The Crown of Lucion is a unique item in Diablo 4 with intriguing features but also significant drawbacks that make it a challenging addition to any build. It offers stats such as 873 maximum life, 6-8% lucky hit chance, 40% shadow resistance, and 8% cooldown reduction.
The item’s key effect increases damage by 5-15% per stack (up to five times) whenever a skill with a resource cost is used, but it also raises resource costs by 30% for five seconds. This can result in a substantial damage boost, but the increased resource consumption may be difficult to manage without additional resource regeneration strategies. While the helmet has potential, its utility is highly dependent on build synergy and the quality of the roll, making it a situational choice rather than a must-have for every player.
Effect
Each time you use a Skill with a Resource Cost, gain [5 - 15]% increased damage and Resource Cost is increased by 30% for 4 seconds, stacking up to 5 times.
How to get Crown of Lucion
You can farm this unique from 
the Fell Council
The prince of Hatred, fair as maggots over carrion. He claims no throne, crafts no realms, reigning over only a blackened, bitter heart. Some legends name him banished, while others dread his return.
Legions
Helltide