Precision Magic

Precision Magic is a passive talent.

In-game
Affects all spells, but only begins to charge up 0.6 seconds after not casting any spells. Once a damaging spell is cast (regardless of if it hits anything), it uses up the entire Precision Magic charge and resets its bonus to zero. Non-damaging casts will not drop it.

For Incinerate, this effect resets only when the channeling stops.

For, only the Sorceress's own attack will reset Precision Magic, therefore Hydra will benefit from it even as its mistress is not casting any other spells.