The Mana Strike node Spark Charges grants a chance on hit to apply a Spark Charge with Mana Strike.
The Starved Strikes and Avatar of Hunger nodes read, “Mana Strike deals more damage while you are out of mana.”
This more damage multiplier is not being applied to Spark Charges generated by Mana Strike. I tested this on dummies the other day for a while.
It is my understanding that since Spark Charges are not an equippable skill, therefore they should inherit the skill tree modifiers for Mana Strike if they are applied by Mana Strike.
https://www.lastepochtools.com/ailments/spark_charge
You are not procing spark’s hit directly, it is an ailment with following spark’s hit