I don't know what's going on technically, so I will simply explain how to reproduce it and the effect it has. My best guess is that the cooldown begins counting down during the duration, but then starts from scratch once the duration has ended.
To reproduce:
1) Activate scarabs and let it expire. Note the cooldown.
2) Activate scarabs and dump the final scarab right before the duration ends. Note the lower cooldown.
Buying (Spiritual Overflow, Soul Rebirth, Enchanter's Barrier, Diviner's Kevlar, Superior Cooldown, Rapid Recharge, Superior Duration, and Magic Carpet) lets the duration be longer than the cooldown. When using the above method, the skill is put into a temporarily unusable state.
Buying (Spiritual Overflow, Enchanter's Barrier, Superior Cooldown, Rapid Recharge, and Superior Duration) lets the duration be just slightly shorter than the cooldown. Dumping the last scarab in that slight window lets the skill be immediately recastable.
Optimising players thus need to keep track of a duration bar and dump the final scarab in a very narrow window, else they face the full cooldown. Hitting it before that window will also give them an accordingly shorter timing. Personally I don't find this fun, and it is incredibly unintuitive.
To reproduce:
1) Activate scarabs and let it expire. Note the cooldown.
2) Activate scarabs and dump the final scarab right before the duration ends. Note the lower cooldown.
Buying (Spiritual Overflow, Soul Rebirth, Enchanter's Barrier, Diviner's Kevlar, Superior Cooldown, Rapid Recharge, Superior Duration, and Magic Carpet) lets the duration be longer than the cooldown. When using the above method, the skill is put into a temporarily unusable state.
Buying (Spiritual Overflow, Enchanter's Barrier, Superior Cooldown, Rapid Recharge, and Superior Duration) lets the duration be just slightly shorter than the cooldown. Dumping the last scarab in that slight window lets the skill be immediately recastable.
Optimising players thus need to keep track of a duration bar and dump the final scarab in a very narrow window, else they face the full cooldown. Hitting it before that window will also give them an accordingly shorter timing. Personally I don't find this fun, and it is incredibly unintuitive.
