An interesting version of Serenity could be levelable:
1. Serenity is broken if the player moves forward, back, left or right. <-- Important
While Serenity is in effect, the player regains 10 focus every 2 seconds, accuracy is increased 1% and dodge is increased 1%. Serenity lasts 6 seconds.
Each level increases Serenity duration by 4 seconds, accuracy by 1% and doge by 0.2%.
@ lvl 85, Serenity duration: 346 seconds, accuracy: +86% and dodge: +18%
Cooldown: 300 seconds