The Coated Blades passive behaves inconsistently with skills which use Shadows to repeat, such as Shadow Cascade. Coated blades added cost will apply every time a shadow uses the skill making it unusable.
Since such skills only cost mana once - when actually using the skill - the added mana cost to shadow clones should be a bug that need fixing.
Steps to reproduce:
- Get points in Coated Blades rogue passive
- Generate some shadows
- Use Shadow Cascade
- Observe mana go into negative